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

# Tools

> Extend your assistant's capabilities with actions it can take during calls.

## Overview

Tools are actions your assistant can perform during a conversation. When the AI determines it needs to take an action (like saving contact info or booking an appointment), it invokes the appropriate tool.

VozAgent provides built-in tools for common actions and supports custom tools for specialized workflows.

## Built-in Tools

These tools are available to all assistants:

### save\_contact `System`

Saves caller information (name, email, phone, company, address) to your contacts. Automatically triggered when the assistant collects contact details.

### end\_call `System`

Gracefully ends the call. The assistant uses this when the conversation is complete and the caller says goodbye.

### transfer\_call

Transfers the call to a human team member. Used when the caller requests to speak with a person or the AI can't handle the request.

### check\_availability / book\_appointment

Checks calendar availability and books appointments. Requires a connected calendar (Cal.com or GoHighLevel).

## Custom Tools

Create custom tools to extend your assistant's capabilities:

* Connect to your CRM to look up customer history
* Query your database for pricing or availability
* Send SMS or email notifications
* Integrate with any API your business uses

**Custom Tool Structure:**

```json theme={null}
{
  "name": "lookup_customer",
  "description": "Look up customer by phone number",
  "parameters": {
    "type": "object",
    "properties": {
      "phone": { "type": "string" }
    },
    "required": ["phone"]
  }
}
```

## Tool Invocation

When the AI decides to use a tool:

1. The AI determines a tool is needed based on conversation context
2. VozAgent calls your tool's webhook endpoint with the parameters
3. Your endpoint processes the request and returns a result
4. The AI uses the result to continue the conversation

Tool invocations are logged and visible in call transcripts for debugging.

[Explore Integrations](/developers/docs/integrations)