# Source: https://gofastmcp.com/python-sdk/fastmcp-server-providers-local_provider-decorators-tools.md

> ## Documentation Index
> Fetch the complete documentation index at: https://gofastmcp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# 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/jlowin/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L31" 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/jlowin/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L39" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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/jlowin/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L78" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
tool(self: LocalProvider, name_or_fn: AnyFunction) -> FunctionTool
```

#### `tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L100" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
tool(self: LocalProvider, name_or_fn: str | None = None) -> Callable[[AnyFunction], FunctionTool]
```

#### `tool` <sup><a href="https://github.com/jlowin/fastmcp/blob/main/src/fastmcp/server/providers/local_provider/decorators/tools.py#L125" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python  theme={"theme":{"light":"snazzy-light","dark":"dark-plus"}}
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.