What cannot be prompted

Although the system prompt is the core of the agent and plays a crucial role in shaping its behavior, it cannot control every aspect of the system. Below are a few examples of areas that cannot be influenced solely through the prompt.

Examples

Item	Description
Voice (speed, volume, pitch)	Determined by the TTS provider (Cartesia/ElevenLabs), not by the prompt
Timing / Pauses	The agent has no sense of time; “wait 2 seconds” is ignored
First Message	Set in the “First Message” field in the agent settings, not in the system prompt
Silence Handling	The idle handler is system behavior; the prompt can only trigger `waitForUserToReturn` as a tool call
Call Outcomes	Extracted from the transcript after the call, not set by the agent during the call
Tool Calls	The prompt defines when a tool is called; the system automatically provides the current parameter definition to the agent

Prompting Cookbook

Feature Cookbooks

Examples

​Examples

Examples