Merge pull request #17908 from BerriAI/litellm_fix-mcp-tool-name-prefix

Litellm fix mcp tool name prefix

litellm/responses/mcp/litellm_proxy_mcp_handler.py

@@ -494,9 +494,21 @@ class LiteLLM_Proxy_MCP_Handler:
 
                 server_name = tool_server_map[tool_name]
 
+                # Remove the server name prefix if the tool name includes it.
+                sanitized_tool_name = tool_name
+                unprefixed_name, prefixed_server_name = split_server_prefix_from_name(
+                    tool_name
+                )
+                if (
+                    prefixed_server_name
+                    and prefixed_server_name == server_name
+                    and unprefixed_name
+                ):
+                    sanitized_tool_name = unprefixed_name
+
                 result = await global_mcp_server_manager.call_tool(
                     server_name=server_name,
-                    name=tool_name,
+                    name=sanitized_tool_name,
                     arguments=parsed_arguments,
                     user_api_key_auth=user_api_key_auth,
                     mcp_auth_header=mcp_auth_header,
@@ -626,6 +638,9 @@ class LiteLLM_Proxy_MCP_Handler:
         function_calls: List[Dict[str, Any]] = []
 
         for output_item in response.output:
+            if not isinstance(output_item, dict) and hasattr(output_item, "model_dump"):
+                output_item = output_item.model_dump()
+
             if isinstance(output_item, dict):
                 if output_item.get("type") == "function_call":
                     call_id = output_item.get("call_id") or output_item.get("id")

tests/test_litellm/responses/mcp/test_litellm_proxy_mcp_handler.py

@@ -1,9 +1,34 @@
+import sys
+import types
+from unittest.mock import AsyncMock
+
 import pytest
 
 from litellm.responses.mcp.litellm_proxy_mcp_handler import (
     LiteLLM_Proxy_MCP_Handler,
 )
 from litellm.types.utils import ModelResponse
+from litellm.types.responses.main import OutputFunctionToolCall
+
+
+class _DummyMCPResult:
+    def __init__(self):
+        self.content = []
+
+
+def _setup_mcp_call_environment(monkeypatch: pytest.MonkeyPatch) -> AsyncMock:
+    """Patch MCP globals so _execute_tool_calls can run in tests."""
+    proxy_module = types.SimpleNamespace(proxy_logging_obj=object())
+    monkeypatch.setitem(sys.modules, "litellm.proxy.proxy_server", proxy_module)
+
+    fake_manager = types.SimpleNamespace(
+        call_tool=AsyncMock(return_value=_DummyMCPResult())
+    )
+    monkeypatch.setattr(
+        "litellm.proxy._experimental.mcp_server.mcp_server_manager.global_mcp_server_manager",
+        fake_manager,
+    )
+    return fake_manager.call_tool
 
 
 def test_deduplicate_mcp_tools_single_allowed_server():
@@ -142,3 +167,93 @@ def test_transform_mcp_tools_to_openai_uses_chat_format(monkeypatch):
     assert resp_tools == [{"responses": True}]
     assert captured["chat"] == ["tool"]
     assert captured["responses"] == ["tool"]
+
+
+def test_create_follow_up_input_handles_response_function_tool_call():
+    response = types.SimpleNamespace(
+        output=[
+            OutputFunctionToolCall(
+                id="id",
+                type="function_call",
+                call_id="call-1",
+                name="foo",
+                arguments="{}",
+                status="completed",
+            )
+        ]
+    )
+
+    follow_up = LiteLLM_Proxy_MCP_Handler._create_follow_up_input(
+        response=response,
+        tool_results=[],
+        original_input=None,
+    )
+
+    assert follow_up == [
+        {
+            "type": "function_call",
+            "call_id": "call-1",
+            "name": "foo",
+            "arguments": "{}",
+        }
+    ]
+
+
+@pytest.mark.asyncio
+async def test_execute_tool_calls_strips_server_prefix(monkeypatch):
+    call_tool_mock = _setup_mcp_call_environment(monkeypatch)
+    tool_name = "deepwiki-read_wiki_structure"
+    tool_calls = [
+        {
+            "id": "call-1",
+            "function": {"name": tool_name, "arguments": "{}"},
+        }
+    ]
+
+    await LiteLLM_Proxy_MCP_Handler._execute_tool_calls(
+        tool_server_map={tool_name: "deepwiki"},
+        tool_calls=tool_calls,
+        user_api_key_auth=None,
+    )
+
+    assert call_tool_mock.await_args.kwargs["name"] == "read_wiki_structure"
+
+
+@pytest.mark.asyncio
+async def test_execute_tool_calls_keeps_tool_name_without_prefix(monkeypatch):
+    call_tool_mock = _setup_mcp_call_environment(monkeypatch)
+    tool_name = "read_wiki_structure"
+    tool_calls = [
+        {
+            "id": "call-2",
+            "function": {"name": tool_name, "arguments": "{}"},
+        }
+    ]
+
+    await LiteLLM_Proxy_MCP_Handler._execute_tool_calls(
+        tool_server_map={tool_name: "deepwiki"},
+        tool_calls=tool_calls,
+        user_api_key_auth=None,
+    )
+
+    assert call_tool_mock.await_args.kwargs["name"] == tool_name
+
+
+@pytest.mark.asyncio
+async def test_execute_tool_calls_keeps_tool_name_when_equal_to_server(monkeypatch):
+    call_tool_mock = _setup_mcp_call_environment(monkeypatch)
+    tool_name = "echo"
+    tool_calls = [
+        {
+            "id": "call-3",
+            "function": {"name": tool_name, "arguments": "{}"},
+        }
+    ]
+
+    await LiteLLM_Proxy_MCP_Handler._execute_tool_calls(
+        tool_server_map={tool_name: "echo"},
+        tool_calls=tool_calls,
+        user_api_key_auth=None,
+    )
+
+    assert call_tool_mock.await_args.kwargs["name"] == tool_name