diff --git a/codegen/src/main/java/software/amazon/awssdk/codegen/docs/DocumentationBuilder.java b/codegen/src/main/java/software/amazon/awssdk/codegen/docs/DocumentationBuilder.java
index 8e91c2493f7d..ea98967d01f5 100644
--- a/codegen/src/main/java/software/amazon/awssdk/codegen/docs/DocumentationBuilder.java
+++ b/codegen/src/main/java/software/amazon/awssdk/codegen/docs/DocumentationBuilder.java
@@ -33,7 +33,9 @@ public final class DocumentationBuilder {
     // TODO This prefix is not suitable for paginated operations. Either remove it for paginated operations
     // or change the statement to something generic
     private static final String ASYNC_THROWS_PREFIX = "The CompletableFuture returned by this method can be completed " +
-                                                      "exceptionally with the following exceptions.";
+                                                      "exceptionally with the following exceptions. The exception returned is "
+                                                      + "wrapped with CompletionException, so you need to invoke {@link "
+                                                      + "Throwable#getCause} to retrieve the underlying exception.";
 
     private String desc;
     private List<Pair<String, String>> params = new ArrayList<>();
diff --git a/codegen/src/test/java/software/amazon/awssdk/codegen/model/intermediate/DocumentationBuilderTest.java b/codegen/src/test/java/software/amazon/awssdk/codegen/model/intermediate/DocumentationBuilderTest.java
index ad83e3bb5264..7bc9cd8dbe0b 100644
--- a/codegen/src/test/java/software/amazon/awssdk/codegen/model/intermediate/DocumentationBuilderTest.java
+++ b/codegen/src/test/java/software/amazon/awssdk/codegen/model/intermediate/DocumentationBuilderTest.java
@@ -67,7 +67,9 @@ public void asyncReturns_FormatsExceptionsInUnorderedList() {
                                                  "\n" +
                                                  "@param paramOne param one docs\n" +
                                                  "@return CompletableFuture of success<br/>\n" +
-                                                 "The CompletableFuture returned by this method can be completed exceptionally with the following exceptions.\n" +
+                                                 "The CompletableFuture returned by this method can be completed exceptionally with the following exceptions. "
+                                                 + "The exception returned is wrapped with CompletionException, "
+                                                 + "so you need to invoke {@link Throwable#getCause} to retrieve the underlying exception.\n" +
                                                  "<ul>\n" +
                                                  "<li>FooException Foo docs</li>\n" +
                                                  "<li>BarException Bar docs</li>\n" +
@@ -87,7 +89,9 @@ public void asyncReturnsWithoutDocsForSuccessReturn_FormatsExceptionsInUnordered
                                                  "\n" +
                                                  "@param paramOne param one docs\n" +
                                                  "@return A CompletableFuture indicating when result will be completed.<br/>\n" +
-                                                 "The CompletableFuture returned by this method can be completed exceptionally with the following exceptions.\n" +
+                                                 "The CompletableFuture returned by this method can be completed exceptionally with the following exceptions. "
+                                                 + "The exception returned is wrapped with CompletionException, so you need to invoke {@link Throwable#getCause} "
+                                                 + "to retrieve the underlying exception.\n" +
                                                  "<ul>\n" +
                                                  "<li>FooException Foo docs</li>\n" +
                                                  "<li>BarException Bar docs</li>\n" +
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-aws-json-async-client-class.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-aws-json-async-client-class.java
index 721da70756f2..9234db871578 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-aws-json-async-client-class.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-aws-json-async-client-class.java
@@ -151,7 +151,8 @@ public JsonUtilities utilities() {
      * @param aPostOperationRequest
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -215,7 +216,8 @@ public CompletableFuture<APostOperationResponse> aPostOperation(APostOperationRe
      * @param aPostOperationWithOutputRequest
      * @return A Java Future containing the result of the APostOperationWithOutput operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -276,7 +278,8 @@ public CompletableFuture<APostOperationWithOutputResponse> aPostOperationWithOut
      * @param eventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -368,7 +371,8 @@ public CompletableFuture<Void> eventStreamOperation(EventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyInput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -435,7 +439,8 @@ public CompletableFuture<EventStreamOperationWithOnlyInputResponse> eventStreamO
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyOutput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -522,7 +527,8 @@ public CompletableFuture<Void> eventStreamOperationWithOnlyOutput(
      * @param getWithoutRequiredMembersRequest
      * @return A Java Future containing the result of the GetWithoutRequiredMembers operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -583,7 +589,8 @@ public CompletableFuture<GetWithoutRequiredMembersResponse> getWithoutRequiredMe
      * @return A Java Future containing the result of the OperationWithChecksumRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -645,7 +652,8 @@ public CompletableFuture<OperationWithChecksumRequiredResponse> operationWithChe
      * @param operationWithNoneAuthTypeRequest
      * @return A Java Future containing the result of the OperationWithNoneAuthType operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -704,7 +712,8 @@ public CompletableFuture<OperationWithNoneAuthTypeResponse> operationWithNoneAut
      * @return A Java Future containing the result of the OperationWithRequestCompression operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -768,7 +777,8 @@ public CompletableFuture<OperationWithRequestCompressionResponse> operationWithR
      * @return A Java Future containing the result of the PaginatedOperationWithResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -827,7 +837,8 @@ public CompletableFuture<PaginatedOperationWithResultKeyResponse> paginatedOpera
      * @return A Java Future containing the result of the PaginatedOperationWithoutResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -890,7 +901,8 @@ public CompletableFuture<PaginatedOperationWithoutResultKeyResponse> paginatedOp
      *        uploading from a file. The service documentation for the request content is as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -962,7 +974,8 @@ public CompletableFuture<StreamingInputOperationResponse> streamingInputOperatio
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1047,7 +1060,8 @@ public <ReturnT> CompletableFuture<ReturnT> streamingInputOutputOperation(
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-json-async-client-class.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-json-async-client-class.java
index b31d21fa7637..88d71aca629a 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-json-async-client-class.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-json-async-client-class.java
@@ -159,7 +159,8 @@ public JsonUtilities utilities() {
      * @param aPostOperationRequest
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -223,7 +224,8 @@ public CompletableFuture<APostOperationResponse> aPostOperation(APostOperationRe
      * @param aPostOperationWithOutputRequest
      * @return A Java Future containing the result of the APostOperationWithOutput operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -283,7 +285,8 @@ public CompletableFuture<APostOperationWithOutputResponse> aPostOperationWithOut
      * @param bearerAuthOperationRequest
      * @return A Java Future containing the result of the BearerAuthOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -341,7 +344,8 @@ public CompletableFuture<BearerAuthOperationResponse> bearerAuthOperation(
      * @param eventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -436,7 +440,8 @@ public CompletableFuture<Void> eventStreamOperation(EventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyInput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -502,7 +507,8 @@ public CompletableFuture<EventStreamOperationWithOnlyInputResponse> eventStreamO
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyOutput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -593,7 +599,8 @@ public CompletableFuture<Void> eventStreamOperationWithOnlyOutput(
      * @param getOperationWithChecksumRequest
      * @return A Java Future containing the result of the GetOperationWithChecksum operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -660,7 +667,8 @@ public CompletableFuture<GetOperationWithChecksumResponse> getOperationWithCheck
      * @param getWithoutRequiredMembersRequest
      * @return A Java Future containing the result of the GetWithoutRequiredMembers operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -721,7 +729,8 @@ public CompletableFuture<GetWithoutRequiredMembersResponse> getWithoutRequiredMe
      * @return A Java Future containing the result of the OperationWithChecksumRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -784,7 +793,8 @@ public CompletableFuture<OperationWithChecksumRequiredResponse> operationWithChe
      * @return A Java Future containing the result of the OperationWithRequestCompression operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -848,7 +858,8 @@ public CompletableFuture<OperationWithRequestCompressionResponse> operationWithR
      * @return A Java Future containing the result of the PaginatedOperationWithResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -907,7 +918,8 @@ public CompletableFuture<PaginatedOperationWithResultKeyResponse> paginatedOpera
      * @return A Java Future containing the result of the PaginatedOperationWithoutResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -983,7 +995,8 @@ public CompletableFuture<PaginatedOperationWithoutResultKeyResponse> paginatedOp
      *        '.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1073,7 +1086,8 @@ public <ReturnT> CompletableFuture<ReturnT> putOperationWithChecksum(
      *        uploading from a file. The service documentation for the request content is as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1145,7 +1159,8 @@ public CompletableFuture<StreamingInputOperationResponse> streamingInputOperatio
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1230,7 +1245,8 @@ public <ReturnT> CompletableFuture<ReturnT> streamingInputOutputOperation(
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-query-async-client-class.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-query-async-client-class.java
index ddf56055a3c6..a78c879fd0ac 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-query-async-client-class.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-query-async-client-class.java
@@ -116,7 +116,8 @@ protected DefaultQueryAsyncClient(SdkClientConfiguration clientConfiguration) {
      * @param aPostOperationRequest
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -175,7 +176,8 @@ public CompletableFuture<APostOperationResponse> aPostOperation(APostOperationRe
      * @param aPostOperationWithOutputRequest
      * @return A Java Future containing the result of the APostOperationWithOutput operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -232,7 +234,8 @@ public CompletableFuture<APostOperationWithOutputResponse> aPostOperationWithOut
      * @param bearerAuthOperationRequest
      * @return A Java Future containing the result of the BearerAuthOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -287,7 +290,8 @@ public CompletableFuture<BearerAuthOperationResponse> bearerAuthOperation(
      * @param getOperationWithChecksumRequest
      * @return A Java Future containing the result of the GetOperationWithChecksum operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -350,7 +354,8 @@ public CompletableFuture<GetOperationWithChecksumResponse> getOperationWithCheck
      * @return A Java Future containing the result of the OperationWithChecksumRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -409,7 +414,8 @@ public CompletableFuture<OperationWithChecksumRequiredResponse> operationWithChe
      * @param operationWithContextParamRequest
      * @return A Java Future containing the result of the OperationWithContextParam operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -464,7 +470,8 @@ public CompletableFuture<OperationWithContextParamResponse> operationWithContext
      * @param operationWithNoneAuthTypeRequest
      * @return A Java Future containing the result of the OperationWithNoneAuthType operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -520,7 +527,8 @@ public CompletableFuture<OperationWithNoneAuthTypeResponse> operationWithNoneAut
      * @return A Java Future containing the result of the OperationWithRequestCompression operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -581,7 +589,8 @@ public CompletableFuture<OperationWithRequestCompressionResponse> operationWithR
      * @return A Java Future containing the result of the OperationWithStaticContextParams operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -654,7 +663,8 @@ public CompletableFuture<OperationWithStaticContextParamsResponse> operationWith
      *        '.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -741,7 +751,8 @@ public <ReturnT> CompletableFuture<ReturnT> putOperationWithChecksum(
      *        uploading from a file. The service documentation for the request content is as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -805,7 +816,8 @@ public CompletableFuture<StreamingInputOperationResponse> streamingInputOperatio
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-xml-async-client-class.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-xml-async-client-class.java
index fa54d4a765c5..444b3789812b 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-xml-async-client-class.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/sra/test-xml-async-client-class.java
@@ -121,7 +121,8 @@ protected DefaultXmlAsyncClient(SdkClientConfiguration clientConfiguration) {
      * @param aPostOperationRequest
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -180,7 +181,8 @@ public CompletableFuture<APostOperationResponse> aPostOperation(APostOperationRe
      * @param aPostOperationWithOutputRequest
      * @return A Java Future containing the result of the APostOperationWithOutput operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -237,7 +239,8 @@ public CompletableFuture<APostOperationWithOutputResponse> aPostOperationWithOut
      * @param bearerAuthOperationRequest
      * @return A Java Future containing the result of the BearerAuthOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -292,7 +295,8 @@ public CompletableFuture<BearerAuthOperationResponse> bearerAuthOperation(
      * @param eventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -372,7 +376,8 @@ public CompletableFuture<Void> eventStreamOperation(EventStreamOperationRequest
      * @param getOperationWithChecksumRequest
      * @return A Java Future containing the result of the GetOperationWithChecksum operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -434,7 +439,8 @@ public CompletableFuture<GetOperationWithChecksumResponse> getOperationWithCheck
      * @return A Java Future containing the result of the OperationWithChecksumRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -492,7 +498,8 @@ public CompletableFuture<OperationWithChecksumRequiredResponse> operationWithChe
      * @param operationWithNoneAuthTypeRequest
      * @return A Java Future containing the result of the OperationWithNoneAuthType operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -548,7 +555,8 @@ public CompletableFuture<OperationWithNoneAuthTypeResponse> operationWithNoneAut
      * @return A Java Future containing the result of the OperationWithRequestCompression operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -625,7 +633,8 @@ public CompletableFuture<OperationWithRequestCompressionResponse> operationWithR
      *        '.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -712,7 +721,8 @@ public <ReturnT> CompletableFuture<ReturnT> putOperationWithChecksum(
      *        uploading from a file. The service documentation for the request content is as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -776,7 +786,8 @@ public CompletableFuture<StreamingInputOperationResponse> streamingInputOperatio
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-abstract-async-client-class.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-abstract-async-client-class.java
index 05c476018466..199e851cd15f 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-abstract-async-client-class.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-abstract-async-client-class.java
@@ -71,7 +71,8 @@ public JsonUtilities utilities() {
      * @param aPostOperationRequest
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -99,7 +100,8 @@ public CompletableFuture<APostOperationResponse> aPostOperation(APostOperationRe
      * @param aPostOperationWithOutputRequest
      * @return A Java Future containing the result of the APostOperationWithOutput operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -126,7 +128,8 @@ public CompletableFuture<APostOperationWithOutputResponse> aPostOperationWithOut
      * @param bearerAuthOperationRequest
      * @return A Java Future containing the result of the BearerAuthOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -151,7 +154,8 @@ public CompletableFuture<BearerAuthOperationResponse> bearerAuthOperation(
      * @param eventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -178,7 +182,8 @@ public CompletableFuture<Void> eventStreamOperation(EventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyInput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -206,7 +211,8 @@ public CompletableFuture<EventStreamOperationWithOnlyInputResponse> eventStreamO
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyOutput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -233,7 +239,8 @@ public CompletableFuture<Void> eventStreamOperationWithOnlyOutput(
      * @param getOperationWithChecksumRequest
      * @return A Java Future containing the result of the GetOperationWithChecksum operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -260,7 +267,8 @@ public CompletableFuture<GetOperationWithChecksumResponse> getOperationWithCheck
      * @param getWithoutRequiredMembersRequest
      * @return A Java Future containing the result of the GetWithoutRequiredMembers operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -288,7 +296,8 @@ public CompletableFuture<GetWithoutRequiredMembersResponse> getWithoutRequiredMe
      * @return A Java Future containing the result of the OperationWithChecksumRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -314,7 +323,8 @@ public CompletableFuture<OperationWithChecksumRequiredResponse> operationWithChe
      * @return A Java Future containing the result of the OperationWithRequestCompression operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -341,7 +351,8 @@ public CompletableFuture<OperationWithRequestCompressionResponse> operationWithR
      * @return A Java Future containing the result of the PaginatedOperationWithResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -368,7 +379,8 @@ public CompletableFuture<PaginatedOperationWithResultKeyResponse> paginatedOpera
      * @return A Java Future containing the result of the PaginatedOperationWithoutResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -412,7 +424,8 @@ public CompletableFuture<PaginatedOperationWithoutResultKeyResponse> paginatedOp
      *        '.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -444,7 +457,8 @@ public <ReturnT> CompletableFuture<ReturnT> putOperationWithChecksum(
      *        uploading from a file. The service documentation for the request content is as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -479,7 +493,8 @@ public CompletableFuture<StreamingInputOperationResponse> streamingInputOperatio
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -511,7 +526,8 @@ public <ReturnT> CompletableFuture<ReturnT> streamingInputOutputOperation(
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-aws-json-async-client-class.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-aws-json-async-client-class.java
index 37a8d4803d1a..dafea08b04e5 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-aws-json-async-client-class.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-aws-json-async-client-class.java
@@ -158,7 +158,8 @@ public JsonUtilities utilities() {
      * @param aPostOperationRequest
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -222,7 +223,8 @@ public CompletableFuture<APostOperationResponse> aPostOperation(APostOperationRe
      * @param aPostOperationWithOutputRequest
      * @return A Java Future containing the result of the APostOperationWithOutput operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -283,7 +285,8 @@ public CompletableFuture<APostOperationWithOutputResponse> aPostOperationWithOut
      * @param eventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -376,7 +379,8 @@ public CompletableFuture<Void> eventStreamOperation(EventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyInput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -445,7 +449,8 @@ public CompletableFuture<EventStreamOperationWithOnlyInputResponse> eventStreamO
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyOutput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -532,7 +537,8 @@ public CompletableFuture<Void> eventStreamOperationWithOnlyOutput(
      * @param getWithoutRequiredMembersRequest
      * @return A Java Future containing the result of the GetWithoutRequiredMembers operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -593,7 +599,8 @@ public CompletableFuture<GetWithoutRequiredMembersResponse> getWithoutRequiredMe
      * @return A Java Future containing the result of the OperationWithChecksumRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -655,7 +662,8 @@ public CompletableFuture<OperationWithChecksumRequiredResponse> operationWithChe
      * @param operationWithNoneAuthTypeRequest
      * @return A Java Future containing the result of the OperationWithNoneAuthType operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -715,7 +723,8 @@ public CompletableFuture<OperationWithNoneAuthTypeResponse> operationWithNoneAut
      * @return A Java Future containing the result of the OperationWithRequestCompression operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -779,7 +788,8 @@ public CompletableFuture<OperationWithRequestCompressionResponse> operationWithR
      * @return A Java Future containing the result of the PaginatedOperationWithResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -838,7 +848,8 @@ public CompletableFuture<PaginatedOperationWithResultKeyResponse> paginatedOpera
      * @return A Java Future containing the result of the PaginatedOperationWithoutResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -901,7 +912,8 @@ public CompletableFuture<PaginatedOperationWithoutResultKeyResponse> paginatedOp
      *        uploading from a file. The service documentation for the request content is as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -976,7 +988,8 @@ public CompletableFuture<StreamingInputOperationResponse> streamingInputOperatio
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1063,7 +1076,8 @@ public <ReturnT> CompletableFuture<ReturnT> streamingInputOutputOperation(
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-aws-query-compatible-json-async-client-class.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-aws-query-compatible-json-async-client-class.java
index 47ef62c35751..6724d5a4da36 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-aws-query-compatible-json-async-client-class.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-aws-query-compatible-json-async-client-class.java
@@ -72,7 +72,8 @@ protected DefaultQueryToJsonCompatibleAsyncClient(SdkClientConfiguration clientC
      * @param aPostOperationRequest
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-custompackage-async.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-custompackage-async.java
index ebcb96eb3c05..0b5006919d4b 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-custompackage-async.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-custompackage-async.java
@@ -67,7 +67,8 @@ protected DefaultProtocolRestJsonWithCustomPackageAsyncClient(SdkClientConfigura
      * @param oneOperationRequest
      * @return A Java Future containing the result of the OneOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-customservicemetadata-async.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-customservicemetadata-async.java
index 88fa5fb4c4bf..832b012265f6 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-customservicemetadata-async.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-customservicemetadata-async.java
@@ -67,7 +67,8 @@ protected DefaultProtocolRestJsonWithCustomContentTypeAsyncClient(SdkClientConfi
      * @param oneOperationRequest
      * @return A Java Future containing the result of the OneOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-endpoint-discovery-async.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-endpoint-discovery-async.java
index a514a7f460e9..8518ad4db2fc 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-endpoint-discovery-async.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-endpoint-discovery-async.java
@@ -88,7 +88,8 @@ protected DefaultEndpointDiscoveryTestAsyncClient(SdkClientConfiguration clientC
      * @param describeEndpointsRequest
      * @return A Java Future containing the result of the DescribeEndpoints operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -144,7 +145,8 @@ public CompletableFuture<DescribeEndpointsResponse> describeEndpoints(DescribeEn
      * @return A Java Future containing the result of the TestDiscoveryIdentifiersRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -225,7 +227,8 @@ public CompletableFuture<TestDiscoveryIdentifiersRequiredResponse> testDiscovery
      * @param testDiscoveryOptionalRequest
      * @return A Java Future containing the result of the TestDiscoveryOptional operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -297,7 +300,8 @@ public CompletableFuture<TestDiscoveryOptionalResponse> testDiscoveryOptional(
      * @param testDiscoveryRequiredRequest
      * @return A Java Future containing the result of the TestDiscoveryRequired operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-json-async-client-class.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-json-async-client-class.java
index 778e6ab56808..0285f56770e7 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-json-async-client-class.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-json-async-client-class.java
@@ -167,7 +167,8 @@ public JsonUtilities utilities() {
      * @param aPostOperationRequest
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -231,7 +232,8 @@ public CompletableFuture<APostOperationResponse> aPostOperation(APostOperationRe
      * @param aPostOperationWithOutputRequest
      * @return A Java Future containing the result of the APostOperationWithOutput operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -291,7 +293,8 @@ public CompletableFuture<APostOperationWithOutputResponse> aPostOperationWithOut
      * @param bearerAuthOperationRequest
      * @return A Java Future containing the result of the BearerAuthOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -350,7 +353,8 @@ public CompletableFuture<BearerAuthOperationResponse> bearerAuthOperation(
      * @param eventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -446,7 +450,8 @@ public CompletableFuture<Void> eventStreamOperation(EventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyInput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -514,7 +519,8 @@ public CompletableFuture<EventStreamOperationWithOnlyInputResponse> eventStreamO
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyOutput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -605,7 +611,8 @@ public CompletableFuture<Void> eventStreamOperationWithOnlyOutput(
      * @param getOperationWithChecksumRequest
      * @return A Java Future containing the result of the GetOperationWithChecksum operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -672,7 +679,8 @@ public CompletableFuture<GetOperationWithChecksumResponse> getOperationWithCheck
      * @param getWithoutRequiredMembersRequest
      * @return A Java Future containing the result of the GetWithoutRequiredMembers operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -733,7 +741,8 @@ public CompletableFuture<GetWithoutRequiredMembersResponse> getWithoutRequiredMe
      * @return A Java Future containing the result of the OperationWithChecksumRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -796,7 +805,8 @@ public CompletableFuture<OperationWithChecksumRequiredResponse> operationWithChe
      * @return A Java Future containing the result of the OperationWithRequestCompression operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -860,7 +870,8 @@ public CompletableFuture<OperationWithRequestCompressionResponse> operationWithR
      * @return A Java Future containing the result of the PaginatedOperationWithResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -919,7 +930,8 @@ public CompletableFuture<PaginatedOperationWithResultKeyResponse> paginatedOpera
      * @return A Java Future containing the result of the PaginatedOperationWithoutResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -995,7 +1007,8 @@ public CompletableFuture<PaginatedOperationWithoutResultKeyResponse> paginatedOp
      *        '.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1088,7 +1101,8 @@ public <ReturnT> CompletableFuture<ReturnT> putOperationWithChecksum(
      *        uploading from a file. The service documentation for the request content is as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1163,7 +1177,8 @@ public CompletableFuture<StreamingInputOperationResponse> streamingInputOperatio
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1250,7 +1265,8 @@ public <ReturnT> CompletableFuture<ReturnT> streamingInputOutputOperation(
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-json-async-client-interface.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-json-async-client-interface.java
index 6508fa3bc790..19078b3e3c35 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-json-async-client-interface.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-json-async-client-interface.java
@@ -86,7 +86,8 @@ default JsonUtilities utilities() {
      * @param aPostOperationRequest
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -123,7 +124,8 @@ default CompletableFuture<APostOperationResponse> aPostOperation(APostOperationR
      *        {@link software.amazon.awssdk.services.json.model.APostOperationRequest.Builder} to create a request.
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -153,7 +155,8 @@ default CompletableFuture<APostOperationResponse> aPostOperation(Consumer<APostO
      * @param aPostOperationWithOutputRequest
      * @return A Java Future containing the result of the APostOperationWithOutput operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -189,7 +192,8 @@ default CompletableFuture<APostOperationWithOutputResponse> aPostOperationWithOu
      *        request.
      * @return A Java Future containing the result of the APostOperationWithOutput operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -216,7 +220,8 @@ default CompletableFuture<APostOperationWithOutputResponse> aPostOperationWithOu
      * @param bearerAuthOperationRequest
      * @return A Java Future containing the result of the BearerAuthOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -246,7 +251,8 @@ default CompletableFuture<BearerAuthOperationResponse> bearerAuthOperation(
      *        {@link software.amazon.awssdk.services.json.model.BearerAuthOperationRequest.Builder} to create a request.
      * @return A Java Future containing the result of the BearerAuthOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -270,7 +276,8 @@ default CompletableFuture<BearerAuthOperationResponse> bearerAuthOperation(
      * @param eventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -301,7 +308,8 @@ default CompletableFuture<Void> eventStreamOperation(EventStreamOperationRequest
      *        request.
      * @return A Java Future containing the result of the EventStreamOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -328,7 +336,8 @@ default CompletableFuture<Void> eventStreamOperation(
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyInput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -361,7 +370,8 @@ default CompletableFuture<EventStreamOperationWithOnlyInputResponse> eventStream
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyInput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -389,7 +399,8 @@ default CompletableFuture<EventStreamOperationWithOnlyInputResponse> eventStream
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyOutput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -422,7 +433,8 @@ default CompletableFuture<Void> eventStreamOperationWithOnlyOutput(
      * @return A Java Future containing the result of the EventStreamOperationWithOnlyOutput operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -449,7 +461,8 @@ default CompletableFuture<Void> eventStreamOperationWithOnlyOutput(
      * @param getOperationWithChecksumRequest
      * @return A Java Future containing the result of the GetOperationWithChecksum operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -480,7 +493,8 @@ default CompletableFuture<GetOperationWithChecksumResponse> getOperationWithChec
      *        request.
      * @return A Java Future containing the result of the GetOperationWithChecksum operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -507,7 +521,8 @@ default CompletableFuture<GetOperationWithChecksumResponse> getOperationWithChec
      * @param getWithoutRequiredMembersRequest
      * @return A Java Future containing the result of the GetWithoutRequiredMembers operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -543,7 +558,8 @@ default CompletableFuture<GetWithoutRequiredMembersResponse> getWithoutRequiredM
      *        request.
      * @return A Java Future containing the result of the GetWithoutRequiredMembers operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -571,7 +587,8 @@ default CompletableFuture<GetWithoutRequiredMembersResponse> getWithoutRequiredM
      * @return A Java Future containing the result of the OperationWithChecksumRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -603,7 +620,8 @@ default CompletableFuture<OperationWithChecksumRequiredResponse> operationWithCh
      * @return A Java Future containing the result of the OperationWithChecksumRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -629,7 +647,8 @@ default CompletableFuture<OperationWithChecksumRequiredResponse> operationWithCh
      * @return A Java Future containing the result of the OperationWithRequestCompression operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -661,7 +680,8 @@ default CompletableFuture<OperationWithRequestCompressionResponse> operationWith
      * @return A Java Future containing the result of the OperationWithRequestCompression operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -687,7 +707,8 @@ default CompletableFuture<OperationWithRequestCompressionResponse> operationWith
      * @return A Java Future containing the result of the PaginatedOperationWithResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -719,7 +740,8 @@ default CompletableFuture<PaginatedOperationWithResultKeyResponse> paginatedOper
      * @return A Java Future containing the result of the PaginatedOperationWithResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -744,7 +766,8 @@ default CompletableFuture<PaginatedOperationWithResultKeyResponse> paginatedOper
      * @return A Java Future containing the result of the PaginatedOperationWithResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -818,7 +841,8 @@ default CompletableFuture<PaginatedOperationWithResultKeyResponse> paginatedOper
      *
      * @return A custom publisher that can be subscribed to request a stream of response pages.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -893,7 +917,8 @@ default PaginatedOperationWithResultKeyPublisher paginatedOperationWithResultKey
      * @param paginatedOperationWithResultKeyRequest
      * @return A custom publisher that can be subscribed to request a stream of response pages.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -977,7 +1002,8 @@ default PaginatedOperationWithResultKeyPublisher paginatedOperationWithResultKey
      *        create a request.
      * @return A custom publisher that can be subscribed to request a stream of response pages.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1003,7 +1029,8 @@ default PaginatedOperationWithResultKeyPublisher paginatedOperationWithResultKey
      * @return A Java Future containing the result of the PaginatedOperationWithoutResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1035,7 +1062,8 @@ default CompletableFuture<PaginatedOperationWithoutResultKeyResponse> paginatedO
      * @return A Java Future containing the result of the PaginatedOperationWithoutResultKey operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1112,7 +1140,8 @@ default CompletableFuture<PaginatedOperationWithoutResultKeyResponse> paginatedO
      * @param paginatedOperationWithoutResultKeyRequest
      * @return A custom publisher that can be subscribed to request a stream of response pages.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1196,7 +1225,8 @@ default PaginatedOperationWithoutResultKeyPublisher paginatedOperationWithoutRes
      *        create a request.
      * @return A custom publisher that can be subscribed to request a stream of response pages.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1239,7 +1269,8 @@ default PaginatedOperationWithoutResultKeyPublisher paginatedOperationWithoutRes
      *        '.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1289,7 +1320,8 @@ default <ReturnT> CompletableFuture<ReturnT> putOperationWithChecksum(
      *        '.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1332,7 +1364,8 @@ default <ReturnT> CompletableFuture<ReturnT> putOperationWithChecksum(
      *        '.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1381,7 +1414,8 @@ default CompletableFuture<PutOperationWithChecksumResponse> putOperationWithChec
      *        '.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1412,7 +1446,8 @@ default CompletableFuture<PutOperationWithChecksumResponse> putOperationWithChec
      *        uploading from a file. The service documentation for the request content is as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1448,7 +1483,8 @@ default CompletableFuture<StreamingInputOperationResponse> streamingInputOperati
      *        uploading from a file. The service documentation for the request content is as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1478,7 +1514,8 @@ default CompletableFuture<StreamingInputOperationResponse> streamingInputOperati
      *        as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1514,7 +1551,8 @@ default CompletableFuture<StreamingInputOperationResponse> streamingInputOperati
      *        as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1549,7 +1587,8 @@ default CompletableFuture<StreamingInputOperationResponse> streamingInputOperati
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1591,7 +1630,8 @@ default <ReturnT> CompletableFuture<ReturnT> streamingInputOutputOperation(
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1628,7 +1668,8 @@ default <ReturnT> CompletableFuture<ReturnT> streamingInputOutputOperation(
      *        The service documentation for the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1669,7 +1710,8 @@ default CompletableFuture<StreamingInputOutputOperationResponse> streamingInputO
      *        The service documentation for the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1701,7 +1743,8 @@ default CompletableFuture<StreamingInputOutputOperationResponse> streamingInputO
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1738,7 +1781,8 @@ default <ReturnT> CompletableFuture<ReturnT> streamingOutputOperation(
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1768,7 +1812,8 @@ default <ReturnT> CompletableFuture<ReturnT> streamingOutputOperation(
      *        The service documentation for the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -1803,7 +1848,8 @@ default CompletableFuture<StreamingOutputOperationResponse> streamingOutputOpera
      *        The service documentation for the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-query-async-client-class.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-query-async-client-class.java
index 11e753cf4dd6..6e94224f3390 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-query-async-client-class.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-query-async-client-class.java
@@ -122,7 +122,8 @@ protected DefaultQueryAsyncClient(SdkClientConfiguration clientConfiguration) {
      * @param aPostOperationRequest
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -181,7 +182,8 @@ public CompletableFuture<APostOperationResponse> aPostOperation(APostOperationRe
      * @param aPostOperationWithOutputRequest
      * @return A Java Future containing the result of the APostOperationWithOutput operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -238,7 +240,8 @@ public CompletableFuture<APostOperationWithOutputResponse> aPostOperationWithOut
      * @param bearerAuthOperationRequest
      * @return A Java Future containing the result of the BearerAuthOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -294,7 +297,8 @@ public CompletableFuture<BearerAuthOperationResponse> bearerAuthOperation(
      * @param getOperationWithChecksumRequest
      * @return A Java Future containing the result of the GetOperationWithChecksum operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -357,7 +361,8 @@ public CompletableFuture<GetOperationWithChecksumResponse> getOperationWithCheck
      * @return A Java Future containing the result of the OperationWithChecksumRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -416,7 +421,8 @@ public CompletableFuture<OperationWithChecksumRequiredResponse> operationWithChe
      * @param operationWithContextParamRequest
      * @return A Java Future containing the result of the OperationWithContextParam operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -471,7 +477,8 @@ public CompletableFuture<OperationWithContextParamResponse> operationWithContext
      * @param operationWithNoneAuthTypeRequest
      * @return A Java Future containing the result of the OperationWithNoneAuthType operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -528,7 +535,8 @@ public CompletableFuture<OperationWithNoneAuthTypeResponse> operationWithNoneAut
      * @return A Java Future containing the result of the OperationWithRequestCompression operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -589,7 +597,8 @@ public CompletableFuture<OperationWithRequestCompressionResponse> operationWithR
      * @return A Java Future containing the result of the OperationWithStaticContextParams operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -662,7 +671,8 @@ public CompletableFuture<OperationWithStaticContextParamsResponse> operationWith
      *        '.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -752,7 +762,8 @@ public <ReturnT> CompletableFuture<ReturnT> putOperationWithChecksum(
      *        uploading from a file. The service documentation for the request content is as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -819,7 +830,8 @@ public CompletableFuture<StreamingInputOperationResponse> streamingInputOperatio
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
diff --git a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-xml-async-client-class.java b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-xml-async-client-class.java
index fb00ce52de6a..72f26c9c44a0 100644
--- a/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-xml-async-client-class.java
+++ b/codegen/src/test/resources/software/amazon/awssdk/codegen/poet/client/test-xml-async-client-class.java
@@ -127,7 +127,8 @@ protected DefaultXmlAsyncClient(SdkClientConfiguration clientConfiguration) {
      * @param aPostOperationRequest
      * @return A Java Future containing the result of the APostOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -186,7 +187,8 @@ public CompletableFuture<APostOperationResponse> aPostOperation(APostOperationRe
      * @param aPostOperationWithOutputRequest
      * @return A Java Future containing the result of the APostOperationWithOutput operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>InvalidInputException The request was rejected because an invalid or out-of-range value was supplied
      *         for an input parameter.</li>
@@ -243,7 +245,8 @@ public CompletableFuture<APostOperationWithOutputResponse> aPostOperationWithOut
      * @param bearerAuthOperationRequest
      * @return A Java Future containing the result of the BearerAuthOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -299,7 +302,8 @@ public CompletableFuture<BearerAuthOperationResponse> bearerAuthOperation(
      * @param eventStreamOperationRequest
      * @return A Java Future containing the result of the EventStreamOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -379,7 +383,8 @@ public CompletableFuture<Void> eventStreamOperation(EventStreamOperationRequest
      * @param getOperationWithChecksumRequest
      * @return A Java Future containing the result of the GetOperationWithChecksum operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -441,7 +446,8 @@ public CompletableFuture<GetOperationWithChecksumResponse> getOperationWithCheck
      * @return A Java Future containing the result of the OperationWithChecksumRequired operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -499,7 +505,8 @@ public CompletableFuture<OperationWithChecksumRequiredResponse> operationWithChe
      * @param operationWithNoneAuthTypeRequest
      * @return A Java Future containing the result of the OperationWithNoneAuthType operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -556,7 +563,8 @@ public CompletableFuture<OperationWithNoneAuthTypeResponse> operationWithNoneAut
      * @return A Java Future containing the result of the OperationWithRequestCompression operation returned by the
      *         service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -633,7 +641,8 @@ public CompletableFuture<OperationWithRequestCompressionResponse> operationWithR
      *        '.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -723,7 +732,8 @@ public <ReturnT> CompletableFuture<ReturnT> putOperationWithChecksum(
      *        uploading from a file. The service documentation for the request content is as follows 'This be a stream'
      * @return A Java Future containing the result of the StreamingInputOperation operation returned by the service.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>
@@ -790,7 +800,8 @@ public CompletableFuture<StreamingInputOperationResponse> streamingInputOperatio
      *        the response content is as follows 'This be a stream'.
      * @return A future to the transformed result of the AsyncResponseTransformer.<br/>
      *         The CompletableFuture returned by this method can be completed exceptionally with the following
-     *         exceptions.
+     *         exceptions. The exception returned is wrapped with CompletionException, so you need to invoke
+     *         {@link Throwable#getCause} to retrieve the underlying exception.
      *         <ul>
      *         <li>SdkException Base class for all exceptions that can be thrown by the SDK (both service and client).
      *         Can be used for catch all scenarios.</li>