From dcc517b187fb8c9ee5ba2584e281e41bf86e23b4 Mon Sep 17 00:00:00 2001
From: Zhou Jing <124344487+starchou6@users.noreply.github.com>
Date: Wed, 10 Sep 2025 00:25:52 +0900
Subject: [PATCH] fix(core): ensure `InjectedToolCallId` always overrides
 LLM-generated values (#32766)

---
 libs/core/langchain_core/tools/base.py   | 10 ++--------
 libs/core/tests/unit_tests/test_tools.py | 22 ++++++++++++++++++++++
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/libs/core/langchain_core/tools/base.py b/libs/core/langchain_core/tools/base.py
index 5f09665c798..81ba71a891a 100644
--- a/libs/core/langchain_core/tools/base.py
+++ b/libs/core/langchain_core/tools/base.py
@@ -659,10 +659,7 @@ class ChildTool(BaseTool):
                 return tool_input
             if issubclass(input_args, BaseModel):
                 for k, v in get_all_basemodel_annotations(input_args).items():
-                    if (
-                        _is_injected_arg_type(v, injected_type=InjectedToolCallId)
-                        and k not in tool_input
-                    ):
+                    if _is_injected_arg_type(v, injected_type=InjectedToolCallId):
                         if tool_call_id is None:
                             msg = (
                                 "When tool includes an InjectedToolCallId "
@@ -677,10 +674,7 @@ class ChildTool(BaseTool):
                 result_dict = result.model_dump()
             elif issubclass(input_args, BaseModelV1):
                 for k, v in get_all_basemodel_annotations(input_args).items():
-                    if (
-                        _is_injected_arg_type(v, injected_type=InjectedToolCallId)
-                        and k not in tool_input
-                    ):
+                    if _is_injected_arg_type(v, injected_type=InjectedToolCallId):
                         if tool_call_id is None:
                             msg = (
                                 "When tool includes an InjectedToolCallId "
diff --git a/libs/core/tests/unit_tests/test_tools.py b/libs/core/tests/unit_tests/test_tools.py
index b296608120a..63d9c30e46d 100644
--- a/libs/core/tests/unit_tests/test_tools.py
+++ b/libs/core/tests/unit_tests/test_tools.py
@@ -2349,6 +2349,28 @@ def test_tool_injected_tool_call_id() -> None:
     ) == ToolMessage(0, tool_call_id="bar")  # type: ignore[arg-type]
 
 
+def test_tool_injected_tool_call_id_override_llm_generated() -> None:
+    """Test that InjectedToolCallId overrides LLM-generated values."""
+
+    @tool
+    def foo(x: int, tool_call_id: Annotated[str, InjectedToolCallId]) -> ToolMessage:
+        """Foo."""
+        return ToolMessage(x, tool_call_id=tool_call_id)  # type: ignore[arg-type]
+
+    # Test that when LLM generates the tool_call_id, it gets overridden
+    result = foo.invoke(
+        {
+            "type": "tool_call",
+            "args": {"x": 0, "tool_call_id": "fake_llm_id"},  # LLM generated this
+            "name": "foo",
+            "id": "real_tool_call_id",  # This should be used instead
+        }
+    )
+
+    # The tool should receive the real tool call ID, not the LLM-generated one
+    assert result == ToolMessage(0, tool_call_id="real_tool_call_id")  # type: ignore[arg-type]
+
+
 def test_tool_uninjected_tool_call_id() -> None:
     @tool
     def foo(x: int, tool_call_id: str) -> ToolMessage: