diff --git a/src/agents/mcp/util.py b/src/agents/mcp/util.py
index bf00cb2b79..e910cfc794 100644
--- a/src/agents/mcp/util.py
+++ b/src/agents/mcp/util.py
@@ -276,6 +276,7 @@ async def get_all_function_tools(
                 run_context,
                 agent,
                 failure_error_function=failure_error_function,
+                reserved_tool_names=reserved_tool_names,
             )
             server_tool_names = {tool.name for tool in server_tools}
             duplicate_tool_names = sorted(server_tool_names & tool_names)