From d6f7dab9e65ae84987e1f90428cd5ad8d8b7fd38 Mon Sep 17 00:00:00 2001
From: davenpi <davenport.ianc@gmail.com>
Date: Tue, 13 May 2025 16:39:04 -0400
Subject: [PATCH 1/2] feat: add support for removing tools from server

---
 src/fastmcp/server/server.py      | 12 ++++++++++++
 src/fastmcp/tools/tool_manager.py | 14 ++++++++++++++
 tests/server/test_server.py       | 19 +++++++++++++++++++
 tests/tools/test_tool_manager.py  | 20 ++++++++++++++++++++
 4 files changed, 65 insertions(+)

diff --git a/src/fastmcp/server/server.py b/src/fastmcp/server/server.py
index b17b4ecf0..90499e99f 100644
--- a/src/fastmcp/server/server.py
+++ b/src/fastmcp/server/server.py
@@ -457,6 +457,18 @@ class FastMCP(Generic[LifespanResultT]):
         )
         self._cache.clear()
 
+    def remove_tool(self, name: str) -> None:
+        """Remove a tool from the server.
+
+        Args:
+            name: The name of the tool to remove
+
+        Raises:
+            NotFoundError: If the tool is not found
+        """
+        self._tool_manager.remove_tool(name)
+        self._cache.clear()
+
     def tool(
         self,
         name: str | None = None,
diff --git a/src/fastmcp/tools/tool_manager.py b/src/fastmcp/tools/tool_manager.py
index 21e38c5f2..3114fa1ae 100644
--- a/src/fastmcp/tools/tool_manager.py
+++ b/src/fastmcp/tools/tool_manager.py
@@ -94,6 +94,20 @@ class ToolManager:
             self._tools[key] = tool
         return tool
 
+    def remove_tool(self, key: str) -> None:
+        """Remove a tool from the server.
+
+        Args:
+            key: The key of the tool to remove
+
+        Raises:
+            NotFoundError: If the tool is not found
+        """
+        if key in self._tools:
+            del self._tools[key]
+        else:
+            raise NotFoundError(f"Tool {key!r} not found.")
+
     async def call_tool(
         self, key: str, arguments: dict[str, Any]
     ) -> list[TextContent | ImageContent | EmbeddedResource]:
diff --git a/tests/server/test_server.py b/tests/server/test_server.py
index ead1dd673..f60959674 100644
--- a/tests/server/test_server.py
+++ b/tests/server/test_server.py
@@ -72,6 +72,25 @@ class TestTools:
         assert len(mcp_tools) == 1
         assert mcp_tools[0].name == "custom_name"
 
+    async def test_remove_tool_successfully(self):
+        """Test that FastMCP.remove_tool removes the tool from the registry."""
+
+        mcp = FastMCP()
+
+        @mcp.tool(name="adder")
+        def add(a: int, b: int) -> int:
+            return a + b
+
+        mcp_tools = await mcp.get_tools()
+        assert "adder" in mcp_tools
+
+        mcp.remove_tool("adder")
+        mcp_tools = await mcp.get_tools()
+        assert "adder" not in mcp_tools
+
+        with pytest.raises(NotFoundError, match="Unknown tool: adder"):
+            await mcp._mcp_call_tool("adder", {"a": 1, "b": 2})
+
 
 class TestToolDecorator:
     async def test_no_tools_before_decorator(self):
diff --git a/tests/tools/test_tool_manager.py b/tests/tools/test_tool_manager.py
index a777b755e..4d61d0520 100644
--- a/tests/tools/test_tool_manager.py
+++ b/tests/tools/test_tool_manager.py
@@ -100,6 +100,26 @@ class TestAddTools:
         ):
             manager.add_tool_from_fn(lambda x: x)
 
+    def test_remove_tool_successfully(self):
+        """Test removing an added tool by key."""
+        manager = ToolManager()
+
+        def add(a: int, b: int) -> int:
+            return a + b
+
+        manager.add_tool_from_fn(add)
+        assert manager.get_tool("add") is not None
+
+        manager.remove_tool("add")
+        with pytest.raises(NotFoundError):
+            manager.get_tool("add")
+
+    def test_remove_tool_missing_key(self):
+        """Test removing a tool that does not exist raises NotFoundError."""
+        manager = ToolManager()
+        with pytest.raises(NotFoundError, match="Tool 'missing' not found"):
+            manager.remove_tool("missing")
+
     def test_warn_on_duplicate_tools(self, caplog):
         """Test warning on duplicate tools."""
         manager = ToolManager(duplicate_behavior="warn")

From a6b7da45993df9c57b2b70aca70a652837b5b63e Mon Sep 17 00:00:00 2001
From: davenpi <davenport.ianc@gmail.com>
Date: Tue, 13 May 2025 16:54:16 -0400
Subject: [PATCH 2/2] chore: unify tool not found error message

---
 src/fastmcp/tools/tool_manager.py | 2 +-
 tests/tools/test_tool_manager.py  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/fastmcp/tools/tool_manager.py b/src/fastmcp/tools/tool_manager.py
index 3114fa1ae..509f4e6de 100644
--- a/src/fastmcp/tools/tool_manager.py
+++ b/src/fastmcp/tools/tool_manager.py
@@ -106,7 +106,7 @@ class ToolManager:
         if key in self._tools:
             del self._tools[key]
         else:
-            raise NotFoundError(f"Tool {key!r} not found.")
+            raise NotFoundError(f"Unknown tool: {key}")
 
     async def call_tool(
         self, key: str, arguments: dict[str, Any]
diff --git a/tests/tools/test_tool_manager.py b/tests/tools/test_tool_manager.py
index 4d61d0520..9d35d177f 100644
--- a/tests/tools/test_tool_manager.py
+++ b/tests/tools/test_tool_manager.py
@@ -117,7 +117,7 @@ class TestAddTools:
     def test_remove_tool_missing_key(self):
         """Test removing a tool that does not exist raises NotFoundError."""
         manager = ToolManager()
-        with pytest.raises(NotFoundError, match="Tool 'missing' not found"):
+        with pytest.raises(NotFoundError, match=f"Unknown tool: {'missing'}"):
             manager.remove_tool("missing")
 
     def test_warn_on_duplicate_tools(self, caplog):