feat: add remove_tool method to FastMCP

Add a remove_tool method to the FastMCP class that allows tools to be
dynamically removed from a server at runtime. This enables use cases
where tools should only be available based on initialization state or
user actions.

The implementation includes:
- remove_tool() method on FastMCP class that wraps the existing
  ToolManager.remove_tool() functionality
- Comprehensive test coverage for tool removal scenarios
- Proper error handling when attempting to remove non-existent tools

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>
Github-Issue: #1322

Author: maxisbey

src/mcp/server/fastmcp/server.py

@@ -374,6 +374,17 @@ def add_tool(
             structured_output=structured_output,
         )
 
+    def remove_tool(self, name: str) -> None:
+        """Remove a tool from the server by name.
+
+        Args:
+            name: The name of the tool to remove
+
+        Raises:
+            ToolError: If the tool does not exist
+        """
+        self._tool_manager.remove_tool(name)
+
     def tool(
         self,
         name: str | None = None,

tests/server/fastmcp/test_server.py

@@ -603,6 +603,80 @@ def get_settings() -> dict[str, str]:
             assert result.isError is False
             assert result.structuredContent == {"theme": "dark", "language": "en", "timezone": "UTC"}
 
+    @pytest.mark.anyio
+    async def test_remove_tool(self):
+        """Test removing a tool from the server."""
+        mcp = FastMCP()
+        mcp.add_tool(tool_fn)
+
+        # Verify tool exists
+        assert len(mcp._tool_manager.list_tools()) == 1
+
+        # Remove the tool
+        mcp.remove_tool("tool_fn")
+
+        # Verify tool is removed
+        assert len(mcp._tool_manager.list_tools()) == 0
+
+    @pytest.mark.anyio
+    async def test_remove_nonexistent_tool(self):
+        """Test that removing a non-existent tool raises ToolError."""
+        from mcp.server.fastmcp.exceptions import ToolError
+
+        mcp = FastMCP()
+
+        with pytest.raises(ToolError, match="Unknown tool: nonexistent"):
+            mcp.remove_tool("nonexistent")
+
+    @pytest.mark.anyio
+    async def test_remove_tool_and_list(self):
+        """Test that a removed tool doesn't appear in list_tools."""
+        mcp = FastMCP()
+        mcp.add_tool(tool_fn)
+        mcp.add_tool(error_tool_fn)
+
+        # Verify both tools exist
+        async with client_session(mcp._mcp_server) as client:
+            tools = await client.list_tools()
+            assert len(tools.tools) == 2
+            tool_names = [t.name for t in tools.tools]
+            assert "tool_fn" in tool_names
+            assert "error_tool_fn" in tool_names
+
+        # Remove one tool
+        mcp.remove_tool("tool_fn")
+
+        # Verify only one tool remains
+        async with client_session(mcp._mcp_server) as client:
+            tools = await client.list_tools()
+            assert len(tools.tools) == 1
+            assert tools.tools[0].name == "error_tool_fn"
+
+    @pytest.mark.anyio
+    async def test_remove_tool_and_call(self):
+        """Test that calling a removed tool fails appropriately."""
+        mcp = FastMCP()
+        mcp.add_tool(tool_fn)
+
+        # Verify tool works before removal
+        async with client_session(mcp._mcp_server) as client:
+            result = await client.call_tool("tool_fn", {"x": 1, "y": 2})
+            assert not result.isError
+            content = result.content[0]
+            assert isinstance(content, TextContent)
+            assert content.text == "3"
+
+        # Remove the tool
+        mcp.remove_tool("tool_fn")
+
+        # Verify calling removed tool returns an error
+        async with client_session(mcp._mcp_server) as client:
+            result = await client.call_tool("tool_fn", {"x": 1, "y": 2})
+            assert result.isError
+            content = result.content[0]
+            assert isinstance(content, TextContent)
+            assert "Unknown tool" in content.text
+
 
 class TestServerResources:
     @pytest.mark.anyio