fix: Fix MCPToolset crashing with anyio.BrokenResourceError

Add error handling for broken resource error so that it retries. Fixes #2769.

Co-authored-by: Kathy Wu <wukathy@google.com>
PiperOrigin-RevId: 829146121

Author: wukath

src/google/adk/tools/mcp_tool/mcp_session_manager.py

@@ -126,9 +126,10 @@ def retry_on_closed_resource(func):
   async def wrapper(self, *args, **kwargs):
     try:
       return await func(self, *args, **kwargs)
-    except anyio.ClosedResourceError:
-      # Simply retry the function - create_session will handle
-      # detecting and replacing disconnected sessions
+    except (anyio.ClosedResourceError, anyio.BrokenResourceError):
+      # If the session connection is closed or unusable, we will retry the
+      # function to reconnect to the server. create_session will handle
+      # detecting and replacing disconnected sessions.
       logger.info('Retrying %s due to closed resource', func.__name__)
       return await func(self, *args, **kwargs)