feat: enhance load_mcp_tools to support loading specific tool names

langchain_mcp_adapters/tools.py

@@ -150,8 +150,14 @@ async def load_mcp_tools(
     session: ClientSession | None,
     *,
     connection: Connection | None = None,
+    tool_names: list[str] | None = None,
 ) -> list[BaseTool]:
-    """Load all available MCP tools and convert them to LangChain tools.
+    """Load selected or all MCP tools and convert them to LangChain tools.
+
+    Args:
+        session: MCP client session
+        connection: Optional connection config to use to create a new session if a `session` is not provided
+        tool_names: List of specific tool names to load. If empty or None, load all tools.
 
     Args:
         session: The MCP client session. If None, connection must be provided.
@@ -176,6 +182,10 @@ async def load_mcp_tools(
     else:
         tools = await _list_all_tools(session)
 
+    # If tool_names is provided and not empty, filter tools by name
+    if tool_names:
+        tools = [tool for tool in tools if tool.name in tool_names]
+
     return [
         convert_mcp_tool_to_langchain_tool(session, tool, connection=connection)
         for tool in tools

tests/test_tools.py

@@ -454,3 +454,71 @@ def custom_httpx_client_factory(
             # Expected to fail since server doesn't have SSE endpoint,
             # but the important thing is that httpx_client_factory was passed correctly
             pass
+
+
+@pytest.mark.asyncio
+async def test_load_mcp_tools_with_no_tool_names_e2e(socket_enabled) -> None:
+    """E2E: Load all MCP tools from a running server."""
+    from mcp.server import FastMCP
+
+    server = FastMCP(port=8184)
+
+    @server.tool()
+    def tool1(param1: str, param2: int) -> str:
+        return f"tool1 result with {param1}, {param2}"
+
+    @server.tool()
+    def tool2(param1: str, param2: int) -> str:
+        return f"tool2 result with {param1}, {param2}"
+
+    @server.tool()
+    def tool3(param1: str, param2: int) -> str:
+        return f"tool3 result with {param1}, {param2}"
+
+    with run_streamable_http(server):
+        client = MultiServerMCPClient(
+            {
+                "alltools": {
+                    "url": "http://localhost:8184/mcp/",
+                    "transport": "streamable_http",
+                },
+            }
+        )
+        async with client.session("alltools") as session:
+            tools = await load_mcp_tools(session)
+            assert len(tools) == 3
+            assert {t.name for t in tools} == {"tool1", "tool2", "tool3"}
+
+
+@pytest.mark.asyncio
+async def test_load_mcp_tools_with_specific_tool_names_e2e(socket_enabled) -> None:
+    """E2E: Load only specific MCP tools from a running server."""
+    from mcp.server import FastMCP
+
+    server = FastMCP(port=8185)
+
+    @server.tool()
+    def tool1(param1: str, param2: int) -> str:
+        return f"tool1 result with {param1}, {param2}"
+
+    @server.tool()
+    def tool2(param1: str, param2: int) -> str:
+        return f"tool2 result with {param1}, {param2}"
+
+    @server.tool()
+    def tool3(param1: str, param2: int) -> str:
+        return f"tool3 result with {param1}, {param2}"
+
+    with run_streamable_http(server):
+        client = MultiServerMCPClient(
+            {
+                "sometools": {
+                    "url": "http://localhost:8185/mcp/",
+                    "transport": "streamable_http",
+                },
+            }
+        )
+        async with client.session("sometools") as session:
+            tools = await load_mcp_tools(session, tool_names=["tool1", "tool3"])
+            assert len(tools) == 2
+            assert {t.name for t in tools} == {"tool1", "tool3"}