# Ponytail Review

> Review code or diffs only for over-engineering. Finds what to delete, replace with stdlib/native features, inline, or shrink. Use when the user asks whether something is over-engineered, what can be deleted, how to simplify a diff, or explicitly invokes ponytail review.

- Skill: `summersec/ponytail-review` (Agent Skill)
- Install (CLI): `npx skillmds@latest add summersec/ponytail-review`
- Raw SKILL.md: https://api.skillmd.com/api/skills/summersec/ponytail-review/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- License: MIT
- Author: summersec (https://skillmd.com/u/summersec)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/summersec/ponytail-review

---


Review diffs for unnecessary complexity. One line per finding: location, what
to cut, what replaces it. The best diff is a shorter diff.

## Format

`L<line>: <tag> <what>. <replacement>.`, or `<file>:L<line>: ...` for multi-file diffs.

Tags:

- `delete:` dead code, unused flexibility, speculative feature. Replacement: nothing.
- `stdlib:` hand-rolled thing the standard library already ships. Name the function.
- `native:` dependency or code doing what the platform already does. Name the feature.
- `yagni:` abstraction with one implementation, config nobody sets, layer with one caller.
- `shrink:` same logic, fewer lines. Show the shorter form.

End with: `net: -<N> lines possible.`

If there is nothing to cut, say `Lean already. Ship.` and stop.

Scope: over-engineering only. Correctness, security, and performance are out of
scope here.