AI agent skill · by @Archive228

Spec First

Write the goal spec on disk before the agent acts, so it can't drift. Use before any multi-step task.

Archived 2026-10-23 · Source updated 2026-07-14 · License: MIT. Check the original repository for the latest version.

SKILL.md instructions

# Spec First
Without an external contract, the agent drifts after ~3 iterations — and the failure looks like progress (code written, tests pass, wrong goal solved).
Write `PROMPT.md` BEFORE acting:
- **Goal** — one sentence.
- **Done when** — concrete, checkable conditions. "Test suite green: <cmd>".
- **Never touch** — files/areas off-limits.
- **Stop if** — more than N files outside scope change; a passing test starts failing.
The agent re-reads this file every iteration. State (what's done) goes in a separate `IMPLEMENTATION_PLAN.md` it updates in place. If you can't write "done when" concretely, the task isn't ready — clarify before coding.