# Ponytail Review

> review, over-engineering, yagni, deletion, simplification

- Skill: `lost-rob0t/ponytail-review` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add lost-rob0t/ponytail-review`
- Raw SKILL.md: https://api.skillmd.com/api/skills/lost-rob0t/ponytail-review/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- License: MIT
- Author: lost-rob0t (https://skillmd.com/u/lost-rob0t)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/lost-rob0t/ponytail-review

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# Ponytail Review

> External import of **Ponytail** by Dietrich Gebert and contributors, adapted from upstream v4.9.0 under MIT.

## Goal

Review a diff only for unnecessary complexity. The best outcome is a shorter diff.

## Input

A code diff or changed-file set.

## Output

One finding per line:

`<file>:L<line>: <tag> <what to cut>. <replacement>.`

Tags:

- `delete:` dead code, unused flexibility, speculative features; replace with nothing.
- `stdlib:` hand-rolled behavior the standard library already provides.
- `native:` dependency or code duplicating a platform feature.
- `yagni:` abstraction with one implementation, config nobody sets, or a layer with one caller.
- `shrink:` same behavior in materially less code.

Rank useful findings first. End with `net: -<N> lines possible.` If nothing should be cut: `Lean already. Ship.`

## Rules

- Scope is over-engineering and complexity only.
- Do not report correctness, security, or performance findings as Ponytail findings; route those to normal review.
- Do not apply fixes unless the user separately asks.
- Do not flag the single minimal runnable check required by Ponytail as bloat.