diff --git a/libs/core/langchain_core/tools.py b/libs/core/langchain_core/tools.py
index d90c19fc2b8..0794613e3ae 100644
--- a/libs/core/langchain_core/tools.py
+++ b/libs/core/langchain_core/tools.py
@@ -580,7 +580,7 @@ class ChildTool(BaseTool):
         if error_to_raise:
             run_manager.on_tool_error(error_to_raise)
             raise error_to_raise
-        output = _format_output(content, artifact, tool_call_id)
+        output = _format_output(content, artifact, tool_call_id, self.name)
         run_manager.on_tool_end(output, color=color, name=self.name, **kwargs)
         return output
 
@@ -672,7 +672,7 @@ class ChildTool(BaseTool):
             await run_manager.on_tool_error(error_to_raise)
             raise error_to_raise
 
-        output = _format_output(content, artifact, tool_call_id)
+        output = _format_output(content, artifact, tool_call_id, self.name)
         await run_manager.on_tool_end(output, color=color, name=self.name, **kwargs)
         return output
 
@@ -1385,7 +1385,7 @@ def _prep_run_args(
 
 
 def _format_output(
-    content: Any, artifact: Any, tool_call_id: Optional[str]
+    content: Any, artifact: Any, tool_call_id: Optional[str], name: str
 ) -> Union[ToolMessage, Any]:
     if tool_call_id:
         # NOTE: This will fail to stringify lists which aren't actually content blocks
@@ -1397,7 +1397,9 @@ def _format_output(
             and isinstance(content[0], (str, dict))
         ):
             content = _stringify(content)
-        return ToolMessage(content, artifact=artifact, tool_call_id=tool_call_id)
+        return ToolMessage(
+            content, artifact=artifact, tool_call_id=tool_call_id, name=name
+        )
     else:
         return content
 
diff --git a/libs/core/tests/unit_tests/test_tools.py b/libs/core/tests/unit_tests/test_tools.py
index b50801ee3a1..9bc15d72d38 100644
--- a/libs/core/tests/unit_tests/test_tools.py
+++ b/libs/core/tests/unit_tests/test_tools.py
@@ -1137,7 +1137,9 @@ def test_tool_call_input_tool_message_output() -> None:
         "type": "tool_call",
     }
     tool = _MockStructuredTool()
-    expected = ToolMessage("1 True {'img': 'base64string...'}", tool_call_id="123")
+    expected = ToolMessage(
+        "1 True {'img': 'base64string...'}", tool_call_id="123", name="structured_api"
+    )
     actual = tool.invoke(tool_call)
     assert actual == expected
 
@@ -1176,7 +1178,9 @@ def test_tool_call_input_tool_message_with_artifact(tool: BaseTool) -> None:
         "id": "123",
         "type": "tool_call",
     }
-    expected = ToolMessage("1 True", artifact=tool_call["args"], tool_call_id="123")
+    expected = ToolMessage(
+        "1 True", artifact=tool_call["args"], tool_call_id="123", name="structured_api"
+    )
     actual = tool.invoke(tool_call)
     assert actual == expected