---
title: "Agents: Reference"
description: "Reference for agent fields, prompt contracts, tool usage, and output constraints."
icon: "book"
mode: "wide"
---

## Agent contract

- `role`: stable operating identity
- `goal`: measurable completion objective
- `backstory`: bounded style and context
- `tools`: allowed action surface

## Output contract

- Prefer structured outputs for machine workflows.
- Define failure behavior for missing tool data.

## Canonical source

Primary API details live in [/en/concepts/agents](/en/concepts/agents).