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, 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
Talkr provides two categories of tools:
Built-in Tools
Pre-configured tools that handle common telephony operations out of the box:
- Call Transfer — Transfer the active call to a phone number or SIP endpoint
- End Call — Terminate the call when the conversation is complete
- Press Digits — Send DTMF keypad tones (PIN, extension, confirmation code) during a live call
Custom Tools
Tools you define to integrate with any external system:
- HTTP API — Call any REST API endpoint during a conversation (e.g., CRM updates, data lookups, triggering automations)
- MCP Tool — Connect an external MCP server and expose its remote tools to the LLM during a conversation
How Tools Work
- You define a tool with a name, description, and parameters
- You attach the tool to one or more workflow nodes
- During a call, the LLM reads your node prompt, the tool description, and the caller's intent to decide whether to invoke the tool
- The tool executes and returns a result that the agent can use to continue the conversation
Filling Dead Air During Tool Calls
A tool that hits a real external system (a custom API, an Integration like Google Calendar or WhatsApp, or an MCP server) takes real time to respond. If the caller shouldn't hear silence while that happens, turn on Tool-Call Filler Audio on the node — it speaks a short phrase you write, in the caller's own language, only when the call actually runs long.
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
Pre-Call Data Fetch
Fetch customer data from your CRM or ERP before the call starts, so your voice agent can greet callers by name and reference their account details.
Tools vs. Connectors
Tools and Connectors both give your agent mid-call capabilities — here's the real difference between them and when to reach for each.