`fastmcp.tools.tool`

Functions

`default_serializer`

default_serializer(data: Any) -> str

Classes

`ToolResult`

Methods:

`to_mcp_result`

to_mcp_result(self) -> list[ContentBlock] | tuple[list[ContentBlock], dict[str, Any]] | CallToolResult

`Tool`

Internal tool registration info. Methods:

`to_mcp_tool`

to_mcp_tool(self, **overrides: Any) -> MCPTool

Convert the FastMCP tool to an MCP tool.

`from_function`

from_function(cls, fn: Callable[..., Any]) -> FunctionTool

Create a Tool from a function.

`run`

run(self, arguments: dict[str, Any]) -> ToolResult

Run the tool with arguments. This method is not implemented in the base Tool class and must be implemented by subclasses. run() can EITHER return a list of ContentBlocks, or a tuple of (list of ContentBlocks, dict of structured output).

`convert_result`

convert_result(self, raw_value: Any) -> ToolResult

Convert a raw result to ToolResult. Handles ToolResult passthrough and converts raw values using the tool’s attributes (serializer, output_schema) for proper conversion.

`register_with_docket`

register_with_docket(self, docket: Docket) -> None

`add_to_docket`

add_to_docket(self, docket: Docket, arguments: dict[str, Any], **kwargs: Any) -> Execution

Schedule this tool for background execution via docket. Args:

docket: The Docket instance
arguments: Tool arguments
fn_key: Function lookup key in Docket registry (defaults to self.key)
task_key: Redis storage key for the result
**kwargs: Additional kwargs passed to docket.add()

`from_tool`

from_tool(cls, tool: Tool) -> TransformedTool

`get_span_attributes`

get_span_attributes(self) -> dict[str, Any]

fastmcp.cli

fastmcp.client

fastmcp.prompts

fastmcp.resources

fastmcp.server

fastmcp.tools

fastmcp.utilities

tool

`fastmcp.tools.tool`

Functions

`default_serializer`

Classes

`ToolResult`

`to_mcp_result`

`Tool`

`to_mcp_tool`

`from_function`

`run`

`convert_result`

`register_with_docket`

`add_to_docket`

`from_tool`

`get_span_attributes`

​fastmcp.tools.tool

​Functions

​default_serializer

​Classes

​ToolResult

​to_mcp_result

​Tool

​to_mcp_tool

​from_function

​run

​convert_result

​register_with_docket

​add_to_docket

​from_tool

​get_span_attributes

`fastmcp.tools.tool`

Functions

`default_serializer`

Classes

`ToolResult`

`to_mcp_result`

`Tool`

`to_mcp_tool`

`from_function`

`run`

`convert_result`

`register_with_docket`

`add_to_docket`

`from_tool`

`get_span_attributes`