diff --git a/libs/langchain_v1/langchain/agents/middleware/tool_retry.py b/libs/langchain_v1/langchain/agents/middleware/tool_retry.py
index 87e20956174..aa7f713f9b6 100644
--- a/libs/langchain_v1/langchain/agents/middleware/tool_retry.py
+++ b/libs/langchain_v1/langchain/agents/middleware/tool_retry.py
@@ -152,7 +152,8 @@ class ToolRetryMiddleware(AgentMiddleware[AgentState[ResponseT], ContextT, Respo
             retry_on: Either a tuple of exception types to retry on, or a callable
                 that takes an exception and returns `True` if it should be retried.
 
-                Default is to retry on all exceptions.
+                Default is to retry on all exceptions. Exceptions that do not match
+                propagate immediately and are not handled by `on_failure`.
             on_failure: Behavior when all retries are exhausted.
 
                 Options: