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

# Tools

> Give an agent actions it can invoke during a call.

Tools let an agent end a call, transfer a caller, retrieve data, or trigger an action in your application. The model chooses a tool from its name, description, and the conversation.

<CardGroup cols={3}>
  <Card title="System tools" icon="gear" href="/agents/system-tools">
    Built-in actions you configure directly on an agent.
  </Card>

  <Card title="Webhook tools" icon="globe" href="/agents/webhook-tools">
    HTTP requests that Cartesia sends to your server.
  </Card>

  <Card title="Client tools" icon="laptop-code" href="/agents/client-tools">
    Functions that your application handles over the WebSocket API.
  </Card>
</CardGroup>

<Frame caption="Add a webhook or client tool from the Tools page in the Playground.">
  <img src="https://mintcdn.com/cartesia-2650f86a/wJ-UNaUxIYqQcebi/assets/images/agents/playground-add-tool.png?fit=max&auto=format&n=wJ-UNaUxIYqQcebi&q=85&s=54d516e18bf4ea9189f45cceca7c7cdc" alt="Add a tool dialog in the Playground offering Webhook and Client function" width="2000" height="1026" data-path="assets/images/agents/playground-add-tool.png" />
</Frame>

## Describe a tool

The model uses a tool's `name` and `description` to decide when to invoke it. State what the tool does and when to use it.

```text theme={null}
Looks up an order by its number. Use it when the caller asks about an order's status or delivery date.
```

## Execution settings

Webhook and client tools share these settings:

| Field                   | Description                                                                                                                                                     |
| ----------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `pre_tool_speech`       | `auto` lets the agent decide whether to speak first. `force` asks it to speak before invoking the tool.                                                         |
| `execution_mode`        | `immediate` runs in the current turn and can be interrupted by the caller. `async` runs separately while the turn can finish.                                   |
| `response_timeout_secs` | Maximum time to wait for a result, from `1` to `120` seconds. The default is `20`. On timeout, the agent continues the conversation with a tool timeout result. |

## Attach tools to an agent

Webhook and client tools are shared resources. Create one with [`POST /v1/agents/tools`](/api-reference/agents/tools/create), then add its ID to `config.tools`. An agent can reference up to 32 tools.

An update to `config.tools` replaces the complete list. A referenced tool cannot be deleted until you remove it from every current agent configuration.

[System tools](/agents/system-tools) are configured separately on `config.system_tools`.