agent-brief

Agent Brief

Source (optional): $ARGUMENTS

Render a brief that another agent implements from. The brief is the contract: whatever discussion, issue thread, or session produced it is context, but the brief is what gets built.

This skill is a renderer, not an investigator. It never interviews the user, never explores the codebase on its own initiative, and never writes to a tracker — it returns markdown, and whoever called it decides where that lands. Invoked directly (/agent-brief), the source is the current conversation.

Principles

• Durable — the brief may sit for weeks while the codebase moves. Describe interfaces, types, and behavioral contracts. Never reference file paths or line numbers, and don't assume today's implementation structure survives.
• Behavioral, not procedural — say what the system should do. The implementing agent explores fresh and decides how.
• Testable — every acceptance criterion must be independently verifiable. "Works correctly" is not a criterion.
• Self-contained — the brief is usually read on a tracker, where the repo's glossary isn't. Use the project's terms, but define any whose meaning a newcomer would guess wrong, and point at CONTEXT.md for the rest.

Template

The heading is always ## Agent Brief, unchanged, so a brief stays recognizable when something re-reads it later.

Each section carries a rule for when it applies. Drop the ones whose rule isn't met — an empty heading is noise.

## Agent Brief

**Summary:** one line — what needs to happen

**Context:**
Why this is being asked for; the problem behind it.

**Current behavior:**
What happens today.

**Starting point:**
Which branch to continue from and what's already on it.

**Desired behavior:**
What should happen once the work is done, including edge cases and error handling.

**Key interfaces:**
- `TypeName` — what changes and why
- `functionName()` — current contract vs desired contract

**Decisions already made:**
- decision — and the reason, so it doesn't get relitigated

**Agent's discretion:**
- open question the implementing agent resolves itself, plus any constraint it must respect

**Acceptance criteria:**
- [ ] specific, independently verifiable criterion

**Out of scope:**
- adjacent thing that must not change