fastmcp.server.providers.local_provider.decorators.tools

Tool decorator mixin for LocalProvider.

This module provides the ToolDecoratorMixin class that adds tool registration functionality to LocalProvider.

Classes

ToolDecoratorMixin ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L118" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

Mixin class providing tool decorator functionality for LocalProvider.

This mixin contains all methods related to:

• Tool registration via add_tool()
• Tool decorator (@provider.tool)

Methods:

add_tool ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L126" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

add_tool(self: LocalProvider, tool: Tool | Callable[..., Any]) -> Tool

Add a tool to this provider's storage.

Accepts either a Tool object or a decorated function with fastmcp metadata.

tool ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L178" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

tool(self: LocalProvider, name_or_fn: F) -> F

tool ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L200" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

tool(self: LocalProvider, name_or_fn: str | None = None) -> Callable[[F], F]

tool ^{<a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L225" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a>}

tool(self: LocalProvider, name_or_fn: str | AnyFunction | None = None) -> Callable[[AnyFunction], FunctionTool] | FunctionTool | partial[Callable[[AnyFunction], FunctionTool] | FunctionTool]

Decorator to register a tool.

This decorator supports multiple calling patterns:

• @provider.tool (without parentheses)
• @provider.tool() (with empty parentheses)
• @provider.tool("custom_name") (with name as first argument)
• @provider.tool(name="custom_name") (with name as keyword argument)
• provider.tool(function, name="custom_name") (direct function call)

Args:

• name_or_fn: Either a function (when used as @tool), a string name, or None
• name: Optional name for the tool (keyword-only, alternative to name_or_fn)
• title: Optional title for the tool
• description: Optional description of what the tool does
• icons: Optional icons for the tool
• tags: Optional set of tags for categorizing the tool
• output_schema: Optional JSON schema for the tool's output
• annotations: Optional annotations about the tool's behavior
• exclude_args: Optional list of argument names to exclude from the tool schema
• meta: Optional meta information about the tool
• enabled: Whether the tool is enabled (default True). If False, adds to blocklist.
• task: Optional task configuration for background execution
• serializer: Deprecated. Return ToolResult from your tools for full control over serialization.

Returns:

• The registered FunctionTool or a decorator function.