diff --git a/og_marl/vault_utils/analyse_vault.py b/og_marl/vault_utils/analyse_vault.py
index 03be0e9f..7c78eef1 100644
--- a/og_marl/vault_utils/analyse_vault.py
+++ b/og_marl/vault_utils/analyse_vault.py
@@ -153,6 +153,14 @@ def describe_episode_returns(
     plot_saving_rel_dir: str = "vaults",
     n_bins: Optional[int] = 50,
 ) -> None:
+    """Describe a vault.
+
+    From the specified directory and for the specified uids,
+    describes vaults according to their episode returns.
+    The descriptors include a table of episode return mean, standard deviation, min and max.
+    Additionally, the distributions of episode returns are visualised in histograms
+    and violin plots. n_bins is how many bins the histogram should have.
+    """
     # get all uids if not specified
     if vault_uids is None:
         vault_uids = get_available_uids(f"./{rel_dir}/{vault_name}")
diff --git a/og_marl/vault_utils/combine_vaults.py b/og_marl/vault_utils/combine_vaults.py
index 420558cf..81690aa4 100644
--- a/og_marl/vault_utils/combine_vaults.py
+++ b/og_marl/vault_utils/combine_vaults.py
@@ -30,6 +30,7 @@ def get_all_vaults(
     vault_uids: Optional[list[str]] = None,
     rel_dir: str = "vaults",
 ) -> list[Vault]:
+    """Gets a list of Vaults from the specified directory. Each uid produces one Vault."""
     if vault_uids is None:
         vault_uids = get_available_uids(f"./{rel_dir}/{vault_name}")
 
@@ -40,6 +41,7 @@ def get_all_vaults(
 
 
 def stitch_vault_from_many(vlts: list[Vault], vault_name: str, vault_uid: str, rel_dir: str) -> int:
+    """Given a list of vaults, writes all experience in each of them to one new vault."""
     all_data = vlts[0].read()
     offline_data = all_data.experience
 
@@ -84,6 +86,11 @@ def stitch_vault_from_many(vlts: list[Vault], vault_name: str, vault_uid: str, r
 
 
 def combine_vaults(rel_dir: str, vault_name: str, vault_uids: Optional[list[str]] = None) -> str:
+    """Combines datasets in a vault.
+
+    Takes multiple datasets in a vault and combines them into one new vault
+    with added "_combined" in the name.
+    """
     # check that the vault to be combined exists
     if not check_directory_exists_and_not_empty(f"./{rel_dir}/{vault_name}"):
         print(f"Vault './{rel_dir}/{vault_name}' does not exist and cannot be combined.")
diff --git a/og_marl/vault_utils/download_vault.py b/og_marl/vault_utils/download_vault.py
index 5d8aa2b6..011e7358 100644
--- a/og_marl/vault_utils/download_vault.py
+++ b/og_marl/vault_utils/download_vault.py
@@ -140,6 +140,7 @@
 
 
 def print_download_options() -> Dict[str, Dict]:
+    """Prints as well as returns all options for downloading vaults from OG-MARL huggingface."""
     print("VAULT_INFO:")
     for source in VAULT_INFO.keys():
         print(f"\t {source}")
@@ -158,6 +159,11 @@ def download_and_unzip_vault(
     dataset_base_dir: str = "./vaults",
     dataset_download_url: str = "",
 ) -> str:
+    """Downloads and unzips vaults.
+
+    The location of the vault is dataset_base_dir/dataset_source/env_name/scenario_name/.
+    If the vault already exists and is not empty, the download does not happen.
+    """
     # to prevent downloading the vault twice into the same folder
     if check_directory_exists_and_not_empty(
         f"{dataset_base_dir}/{dataset_source}/{env_name}/{scenario_name}.vlt"
@@ -215,6 +221,7 @@ def download_and_unzip_vault(
 
 
 def check_directory_exists_and_not_empty(path: str) -> bool:
+    """Checks that the directory at path exists and is not empty."""
     # Check if the directory exists
     if os.path.exists(path) and os.path.isdir(path):
         # Check if the directory is not empty
@@ -227,6 +234,7 @@ def check_directory_exists_and_not_empty(path: str) -> bool:
 
 
 def get_available_uids(rel_vault_path: str) -> List[str]:
+    """Obtains the uids of datasets in a vault at the relative path."""
     vault_uids = sorted(
         next(os.walk(rel_vault_path))[1],
         reverse=True,
diff --git a/og_marl/vault_utils/subsample_bespoke.py b/og_marl/vault_utils/subsample_bespoke.py
index ea07d470..ccaa7558 100644
--- a/og_marl/vault_utils/subsample_bespoke.py
+++ b/og_marl/vault_utils/subsample_bespoke.py
@@ -21,6 +21,7 @@
 
 # given bin edges and a sorted array of values, get the bin number per value
 def get_bin_numbers(sorted_values: Array, bin_edges: Array) -> Array:
+    """Assigns known, sorted values to given bins."""
     bin_numbers = np.zeros_like(sorted_values)
 
     def get_bin_number(bin_num: int, value: float) -> int:
@@ -46,6 +47,12 @@ def get_bin_number(bin_num: int, value: float) -> int:
 def bin_processed_data(
     all_sorted_return_start_end: Array, n_bins: int = 500
 ) -> Tuple[Array, Array, Array, Array, Array]:
+    """Bins rows in an array according to the values in a particular column.
+
+    Returns bar_labels connected with bar_heights,
+    as well as padded_heights whose entries' indices are the bin number.
+    Bin edges and all numbers are also returned.
+    """
     # get bin edges, including final endpoint
     bin_edges = jnp.linspace(
         start=min(min(all_sorted_return_start_end[:, 0]), 0),
@@ -68,9 +75,16 @@ def bin_processed_data(
     return bar_labels, bar_heights, padded_heights.astype(int), bin_edges, bin_numbers
 
 
-# sample from pdf according to heights
-# BIG NOTE: CHECK THE DISPARITY, OTHERWISE YOUR DISTRIBUTION WILL BE TOO MUCH
 def episode_idxes_sampled_from_pdf(pdf: Array, bar_heights: Array) -> list[int]:
+    """Gets a list of episode indices according to how many episodes you want from each bin.
+
+    Given an array of desired bar heights and the actual bar heights, produces the
+    indices of the episodes which should be sampled to produce the desired bar heights.
+    It is assumed that episodes which will be sampled are sorted ascending, and so, for example,
+    with bars of heights 3,5,7 if you want a resultant histogram of 0,2,0, you will need to
+    sample two indices randomly from {3,4,5,6,7}.
+    The function will then return the list of sampled indices.
+    """
     num_to_sample = np.round(pdf).astype(int)
     sample_range_edges = np.concatenate([[0], np.cumsum(bar_heights)])
 
diff --git a/og_marl/vault_utils/subsample_similar.py b/og_marl/vault_utils/subsample_similar.py
index 94209544..90508b2a 100644
--- a/og_marl/vault_utils/subsample_similar.py
+++ b/og_marl/vault_utils/subsample_similar.py
@@ -27,6 +27,11 @@
 
 # cumulative summing per-episode
 def get_episode_returns_and_term_idxes(offline_data: Dict[str, Array]) -> Tuple[Array, Array]:
+    """Gets the episode returns and final indices from a batch of experience.
+
+    From a batch of experience extract the indices
+    of the final transitions as well as the returns of each episode in order.
+    """
     rewards = offline_data["rewards"][0, :, 0]
     terminal_flag = offline_data["terminals"][0, :, ...].all(axis=-1)
 
@@ -49,13 +54,17 @@ def scan_cumsum(
     return cumsums[term_idxes - 1], term_idxes
 
 
-# first store indices of episodes, then sort by episode return.
-# outputs return, start, end and vault index in vault list
 def sort_concat(returns: Array, eps_ends: Array) -> Array:
+    """An original-order-aware sorting and concatenating of episode information.
+
+    From a list of episodes ends and returns which are in the order of the episodes in the
+    original experience batch, produces an array of rows of return,
+    start index and end index for each episode.
+    """
+    # build start indexes from end indexes since they are in order
     episode_start_idxes = eps_ends[:-1] + 1
     episode_start_idxes = jnp.insert(episode_start_idxes, 0, 0).reshape(-1, 1)
     sorting_idxes = jnp.lexsort(jnp.array([returns[:, 0]]), axis=-1)
-    # print(sorting_idxes)
 
     return_start_end = jnp.concatenate(
         [returns, episode_start_idxes.reshape(-1, 1), eps_ends], axis=-1
@@ -69,6 +78,15 @@ def sort_concat(returns: Array, eps_ends: Array) -> Array:
 def get_idxes_of_similar_subsets(
     base_returns: List, comp_returns: List, tol: float = 0.1
 ) -> Tuple[List, List]:
+    """Gets indices of episodes s.t. the subsets of two datasets have similar return distributions.
+
+    Iteratively selects episodes from either dataset with episode return within "tol" of each other.
+    Importantly, returns are SORTED BEFORE BEING PASSED TO THIS FUNCTION.
+    Returns the list of all such almost-matching episodes.
+    (For each episode Ea in dataset A, if there is an episode Eb in dataset B with a return within
+    "tol" of the return of E, select Ea and Eb to be sampled.
+    If not, move on from Ea.)
+    """
     base_selected_idxes = []
     comp_selected_idxes = []
 
@@ -98,6 +116,7 @@ def subsample_similar(
     new_rel_dir: str,
     new_vault_name: str,
 ) -> None:
+    """Subsamples 2 datasets s.t. the new datasets have similar episode return distributions."""
     # check that a subsampled vault by the same name does not already exist
     if check_directory_exists_and_not_empty(f"./{new_rel_dir}/{new_vault_name}"):
         print(
diff --git a/og_marl/vault_utils/subsample_smaller.py b/og_marl/vault_utils/subsample_smaller.py
index 0f10ed8a..4566a917 100644
--- a/og_marl/vault_utils/subsample_smaller.py
+++ b/og_marl/vault_utils/subsample_smaller.py
@@ -31,6 +31,12 @@
 
 
 def get_length_start_end(experience: Dict[str, Array], terminal_key: str = "terminals") -> Array:
+    """Process experience to get the length, start and end of all episodes.
+
+    From a block of experience, extracts the length, start position and end position of each
+    episode. Length is stored for the convenience of a cumsum in the following function, and
+    to match other episode information blocks which store return, instead.
+    """
     # extract terminals
     terminal_flag = experience[terminal_key][0, :, ...].all(axis=-1)
 
@@ -41,7 +47,7 @@ def get_length_start_end(experience: Dict[str, Array], terminal_key: str = "term
     start_idxes = np.zeros_like(term_idxes)
     start_idxes[1:] = term_idxes[:-1]
 
-    # get the length per-episode (TODO maybe redundant)
+    # get the length per-episode
     lengths = term_idxes - start_idxes
 
     # concatenate for easier unpacking
@@ -51,6 +57,13 @@ def get_length_start_end(experience: Dict[str, Array], terminal_key: str = "term
 
 
 def select_episodes_uniformly_up_to_n_transitions(len_start_end: Array, n: int) -> Array:
+    """Uniformly selects episodes from an episode info array.
+
+    Selects rows (episodes) randomly uniformly from an array containing
+    episode lengths, start indices and end indices.
+    Shuffles the indices of the array, then selects the first x shuffled rows
+    up til the cumulative sum of their lengths exceeds n.
+    """
     # shuffle idxes of all the episodes from the vault
     shuffled_idxes = np.arange(len_start_end.shape[0])
     np.random.shuffle(shuffled_idxes)
@@ -69,7 +82,6 @@ def select_episodes_uniformly_up_to_n_transitions(len_start_end: Array, n: int)
     return randomly_sampled_len_start_end
 
 
-# given the indices of the required episodes, stitch a vault and save under a user-specified name
 def stitch_vault_from_sampled_episodes_(
     experience: Dict[str, Array],
     len_start_end_sample: Array,
@@ -78,6 +90,16 @@ def stitch_vault_from_sampled_episodes_(
     rel_dir: str,
     n: int = 500_000,
 ) -> int:
+    """Writes a vault given episode information and a batch of experience.
+
+    Takes in experience
+    and an array with columns R,S,E (reward, start, end) or L, S, E (length, start, end)
+    describing episode returns (or redundantly lengths) and their positions in the block of
+    experience.
+    For every row in len_start_end_sample (for every episode in the sample),
+    selects the relevant transitions from "experience" and adds it to a new buffer.
+    In the end, writes the buffer of all episodes to the destination vault.
+    """
     # to prevent downloading the vault twice into the same folder
     if check_directory_exists_and_not_empty(f"{rel_dir}/{dest_vault_name}/{vault_uid}/"):
         print(f"Vault '{rel_dir}/{dest_vault_name}.vlt/{vault_uid}' already exists.")
@@ -125,6 +147,15 @@ def subsample_smaller_vault(
     vault_uids: Optional[list] = None,
     target_number_of_transitions: int = 500000,
 ) -> str:
+    """Subsamples a vault to a smaller number of transitions.
+
+    Subsamples every dataset in the list of uids (or, if unspecified, all uids in the vault)
+    by uniformly randomly selecting episodes from that dataset and storing it in a new vault.
+
+    Once the number of transitions in the episode selection is within one trajectory length
+    of the desired number of transitions, no further transitions are included.
+    This is to avoid creating partial trajectories.
+    """
     # check that the vault to be subsampled exists
     if not check_directory_exists_and_not_empty(f"./{vaults_dir}/{vault_name}"):
         print(f"Vault './{vaults_dir}/{vault_name}' does not exist and cannot be subsampled.")