> ## Documentation Index
> Fetch the complete documentation index at: https://openrouter-d02e98a0-mintlify-7021d5f4.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# ChatFunctionToolFunctionFunction - Python SDK

> ChatFunctionToolFunctionFunction method reference

<Warning>
  The Python SDK and docs are currently in beta.
  Report issues on [GitHub](https://github.com/OpenRouterTeam/python-sdk/issues).
</Warning>

Function definition for tool calling

## Fields

| Field         | Type                         | Required             | Description                                                      | Example                                                                                                                                                      |
| ------------- | ---------------------------- | -------------------- | ---------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `description` | *Optional\[str]*             | :heavy\_minus\_sign: | Function description for the model                               | Get the current weather for a location                                                                                                                       |
| `name`        | *str*                        | :heavy\_check\_mark: | Function name (a-z, A-Z, 0-9, underscores, dashes, max 64 chars) | get\_weather                                                                                                                                                 |
| `parameters`  | Dict\[str, *Nullable\[Any]*] | :heavy\_minus\_sign: | Function parameters as JSON Schema object                        | `{"properties": {"location": {"description": "City name","type": "string"}`<br />},<br />"required": \[<br />"location"<br />],<br />"type": "object"<br />} |
| `strict`      | *OptionalNullable\[bool]*    | :heavy\_minus\_sign: | Enable strict schema adherence                                   | false                                                                                                                                                        |