> ## 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 - Go SDK

> ChatFunctionToolFunctionFunction type definition

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

Function definition for tool calling

## Fields

| Field         | Type                                       | Required             | Description                                                      | Example                                                                                                                                                      |
| ------------- | ------------------------------------------ | -------------------- | ---------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `Description` | `*string`                                  | :heavy\_minus\_sign: | Function description for the model                               | Get the current weather for a location                                                                                                                       |
| `Name`        | `string`                                   | :heavy\_check\_mark: | Function name (a-z, A-Z, 0-9, underscores, dashes, max 64 chars) | get\_weather                                                                                                                                                 |
| `Parameters`  | map\[string]`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.OptionalNullable\[`bool`] | :heavy\_minus\_sign: | Enable strict schema adherence                                   | false                                                                                                                                                        |