---
title: tools
sidebarTitle: tools
---

# `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` <sup><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></sup>


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` <sup><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></sup>

```python
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` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L179" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

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

#### `tool` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L202" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

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

#### `tool` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L228" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
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.

