Merge pull request #860 from rsp2k/rsp2k-patch-1

contrib.mcp_mixin: add support for enabled, mcp_tool: annotations, excl. parm, serializer

src/fastmcp/contrib/mcp_mixin/README.md

@@ -1,26 +1,103 @@
+from mcp.types import ToolAnnotations
+
 # MCP Mixin
 
 This module provides the `MCPMixin` base class and associated decorators (`@mcp_tool`, `@mcp_resource`, `@mcp_prompt`).
 
 It allows developers to easily define classes whose methods can be registered as tools, resources, or prompts with a `FastMCP` server instance using the `register_all()`, `register_tools()`, `register_resources()`, or `register_prompts()` methods provided by the mixin.
 
+Includes support for
+Tools:
+* [enable/disable](https://gofastmcp.com/servers/tools#disabling-tools)
+* [annotations](https://gofastmcp.com/servers/tools#annotations-2)
+* [excluded arguments](https://gofastmcp.com/servers/tools#excluding-arguments)
+
+Prompts:
+* [enable/disable](https://gofastmcp.com/servers/prompts#disabling-prompts)
+
+Resources:
+* [enable/disabe](https://gofastmcp.com/servers/resources#disabling-resources)
+  
 ## Usage
 
 Inherit from `MCPMixin` and use the decorators on the methods you want to register.
 
 ```python
+from mcp.types import ToolAnnotations
 from fastmcp import FastMCP
-from fastmcp.contrib.mcp_mixin import MCPMixin, mcp_tool, mcp_resource
+from fastmcp.contrib.mcp_mixin import MCPMixin, mcp_tool, mcp_resource, mcp_prompt
 
 class MyComponent(MCPMixin):
     @mcp_tool(name="my_tool", description="Does something cool.")
     def tool_method(self):
         return "Tool executed!"
 
+    # example of disabled tool
+    @mcp_tool(name="my_tool", description="Does something cool.", enabled=False)
+    def disabled_tool_method(self):
+        # This function can't be called by client because it's disabled
+        return "You'll never get here!"
+
+    # example of excluded parameter tool
+    @mcp_tool(
+        name="my_tool", description="Does something cool.",
+        enabled=False, exclude_args=['delete_everything'],
+    )
+    def excluded_param_tool_method(self, delete_everything=False):
+        # MCP tool calls can't pass the "delete_everything" argument
+        if delete_everything:
+            return "Nothing to delete, I bet you're not a tool :)"
+        return "You might be a tool if..."
+
+    # example tool w/annotations
+    @mcp_tool(
+        name="my_tool", description="Does something cool.",
+        annotations=ToolAnnotations(
+            title="Attn LLM, use this tool first!",
+            readOnlyHint=False,
+            destructiveHint=False,
+            idempotentHint=False,
+        )
+    )
+    def tool_method(self):
+        return "Tool executed!"
+
+    # example tool w/everything
+    @mcp_tool(
+        name="my_tool", description="Does something cool.",
+        enabled=True,
+        exclude_args=['delete_all'],
+        annotations=ToolAnnotations(
+            title="Attn LLM, use this tool first!",
+            readOnlyHint=False,
+            destructiveHint=False,
+            idempotentHint=False,
+        )
+    )
+    def tool_method(self, delete_all=False):
+        if delete_all:
+            return "99 records deleted. I bet you're not a tool :)"
+        return "Tool executed, but you might be a tool!"
+    
     @mcp_resource(uri="component://data")
     def resource_method(self):
         return {"data": "some data"}
 
+    # Disabled resource
+    @mcp_resource(uri="component://data", enabled=False)
+    def resource_method(self):
+        return {"data": "some data"}
+
+    # prompt
+    @mcp_prompt(name="A prompt")
+    def prompt_method(self, name):
+        return f"Whats up {name}?"
+
+    # disabled prompt
+    @mcp_prompt(name="A prompt", enabled=False)
+    def prompt_method(self, name):
+        return f"Whats up {name}?"
+
 mcp_server = FastMCP()
 component = MyComponent()
 
@@ -36,4 +113,4 @@ component.register_all(mcp_server, prefix="my_comp")
 # Or 'my_tool' and 'component://data' are registered (if no prefix used)
 ```
 
-The `prefix` argument in registration methods is optional. If omitted, methods are registered with their original decorated names/URIs. Individual separators (`tools_separator`, `resources_separator`, `prompts_separator`) can also be provided to `register_all` to change the separator for specific types.
+The `prefix` argument in registration methods is optional. If omitted, methods are registered with their original decorated names/URIs. Individual separators (`tools_separator`, `resources_separator`, `prompts_separator`) can also be provided to `register_all` to change the separator for specific types.

src/fastmcp/contrib/mcp_mixin/mcp_mixin.py

@@ -3,6 +3,8 @@
 from collections.abc import Callable
 from typing import TYPE_CHECKING, Any
 
+from mcp.types import ToolAnnotations
+
 from fastmcp.prompts.prompt import Prompt
 from fastmcp.resources.resource import Resource
 from fastmcp.tools.tool import Tool
@@ -23,6 +25,10 @@ def mcp_tool(
     name: str | None = None,
     description: str | None = None,
     tags: set[str] | None = None,
+    annotations: ToolAnnotations | dict[str, Any] | None = None,
+    exclude_args: list[str] | None = None,
+    serializer: Callable[[Any], str] | None = None,
+    enabled: bool | None = None,
 ) -> Callable[[Callable[..., Any]], Callable[..., Any]]:
     """Decorator to mark a method as an MCP tool for later registration."""
 
@@ -31,6 +37,10 @@ def mcp_tool(
             "name": name or func.__name__,
             "description": description,
             "tags": tags,
+            "annotations": annotations,
+            "exclude_args": exclude_args,
+            "serializer": serializer,
+            "enabled": enabled,
         }
         call_args = {k: v for k, v in call_args.items() if v is not None}
         setattr(func, _MCP_REGISTRATION_TOOL_ATTR, call_args)
@@ -46,6 +56,7 @@ def mcp_resource(
     description: str | None = None,
     mime_type: str | None = None,
     tags: set[str] | None = None,
+    enabled: bool | None = None,
 ) -> Callable[[Callable[..., Any]], Callable[..., Any]]:
     """Decorator to mark a method as an MCP resource for later registration."""
 
@@ -56,6 +67,7 @@ def mcp_resource(
             "description": description,
             "mime_type": mime_type,
             "tags": tags,
+            "enabled": enabled,
         }
         call_args = {k: v for k, v in call_args.items() if v is not None}
 
@@ -70,6 +82,7 @@ def mcp_prompt(
     name: str | None = None,
     description: str | None = None,
     tags: set[str] | None = None,
+    enabled: bool | None = None,
 ) -> Callable[[Callable[..., Any]], Callable[..., Any]]:
     """Decorator to mark a method as an MCP prompt for later registration."""
 
@@ -78,6 +91,7 @@ def mcp_prompt(
             "name": name or func.__name__,
             "description": description,
             "tags": tags,
+            "enabled": enabled,
         }
 
         call_args = {k: v for k, v in call_args.items() if v is not None}