diff --git a/simpletool/__init__.py b/simpletool/__init__.py
index b99672c..2aeb669 100644
--- a/simpletool/__init__.py
+++ b/simpletool/__init__.py
@@ -40,7 +40,7 @@ async def execute(self, arguments: Dict[str, Any]) -> Union[List[Union[ImageCont
         # Fallback to default implementation
         raise NotImplementedError("Tool must implement either 'run' or 'execute' async method")
 
-    def _select_random_api_key(self, env_name:str, env_value: str) -> str:
+    def _select_random_api_key(self, env_name: str, env_value: str) -> str:
         """ Select random api key from env_value only if env_name contains 'API' and 'KEY' """
         if 'API' in env_name.upper() and 'KEY' in env_name.upper():
             api_keys = list(filter(bool, [key.strip() for key in env_value.split(',')]))
diff --git a/simpletool/types.py b/simpletool/types.py
index 1ae071a..36b9977 100644
--- a/simpletool/types.py
+++ b/simpletool/types.py
@@ -9,12 +9,14 @@ class Content(BaseModel):
     type: Literal["text", "image", "resource"]
     model_config = ConfigDict(extra="allow")
 
+
 class TextContent(BaseModel):
     """Text content for a message."""
     type: Literal["text"]
     text: str
     model_config = ConfigDict(extra="allow")
 
+
 class ImageContent(BaseModel):
     """Image content for a message."""
     type: Literal["image"]
@@ -22,20 +24,24 @@ class ImageContent(BaseModel):
     mime_type: str = Field(alias="mimeType")
     model_config = ConfigDict(extra="allow")
 
+
 class ResourceContents(BaseModel):
     """The contents of a resource, embedded into a prompt or tool call result."""
     uri: AnyUrl
     mime_type: str | None = Field(None, alias="mimeType")
     model_config = ConfigDict(extra="allow")
 
+
 class TextResourceContents(ResourceContents):
     """ Tee contents of a text resource, embedded into a prompt or tool call result."""
     text: str
 
+
 class BlobResourceContents(ResourceContents):
     """ The contents of a blob resource, embedded into a prompt or tool call result."""
     blob: str
 
+
 class EmbeddedResource(BaseModel):
     """
     The contents of a resource, embedded into a prompt or tool call result.
@@ -52,5 +58,5 @@ class ErrorData(BaseModel):
     """Error information for JSON-RPC error responses."""
     code: int = Field(description="A number that indicates the error type that occurred.")
     message: str = Field(description="A short description of the error. The message SHOULD be limited to a concise single sentence.")
-    data: Any | None = Field(default=None, description="Additional information about the error. The value of this member is defined by the sender (e.g. detailed error information, nested errors etc.).")
-    model_config = ConfigDict(extra="allow")
\ No newline at end of file
+    data: Any | None = Field(default=None, description="Additional information about the error.")
+    model_config = ConfigDict(extra="allow")