# Tools

> Extend your voice agent's capabilities by giving it tools to perform actions during live conversations.

Tools let your AI agent take actions during a conversation — transfer calls, end calls, look up the current time, call external APIs, or invoke remote MCP servers — based on the context of the conversation and your prompt instructions.

When a tool is attached to a workflow node, the LLM decides **when** to invoke it and **what parameters** to pass, based on the user's spoken intent and your node-level instructions.

## Tool Types

Menace Voice provides two categories of tools:

### Built-in Tools

Pre-configured tools that handle common telephony operations out of the box:

- [**Call Transfer**](/voice-agent/tools/call-transfer) — Transfer the active call to a phone number or SIP endpoint
- [**End Call**](/voice-agent/tools/end-call) — Terminate the call when the conversation is complete
- [**Current Time**](/voice-agent/tools/current-time) — Look up the current time or convert a time between timezones

### Custom Tools

Tools you define to integrate with any external system:

- [**HTTP API**](/voice-agent/tools/http-api) — Call any REST API endpoint during a conversation (e.g., CRM updates, data lookups, triggering automations)
- [**MCP Tool**](/voice-agent/tools/mcp-tool) — Connect an external MCP server and expose its remote tools to the LLM during a conversation

## How Tools Work

1. You **define** a tool with a name, description, and parameters
2. You **attach** the tool to one or more workflow nodes
3. During a call, the LLM reads your node prompt, the tool description, and the caller's intent to decide whether to invoke the tool
4. The tool executes and returns a result that the agent can use to continue the conversation

## Best Practices

- **Attach only relevant tools to each node** — fewer tools means more reliable invocations
- **Write clear tool descriptions** — the LLM uses these to decide when to call the tool
- **Guide the LLM in your node prompt** — explicitly describe when a tool should be used
- **Test tool behavior** — verify your agent invokes tools at the right moments using web or phone calls