diff --git a/src/google/adk/tools/base_tool.py b/src/google/adk/tools/base_tool.py
index 88e9b1ea..4f9e4f3f 100644
--- a/src/google/adk/tools/base_tool.py
+++ b/src/google/adk/tools/base_tool.py
@@ -73,7 +73,7 @@ async def run_async(
 
     Args:
       args: The LLM-filled arguments.
-      ctx: The context of the tool.
+      tool_context: The context of the tool.
 
     Returns:
       The result of running the tool.