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Ponytail Review

dietrichgebert/ponytail-ponytail-review

> reinvented standard library, unneeded dependencies, speculative abstractions, it. Use when the user says "review for over-engineering", "what can we delete", "is this over-engineered", "simplify review", or invokes /ponytail-review. Complements correctness-focused review, this one only hunts complexity.

595 tokens
context cost
the whole folder, loaded on every use
1
files
instructions only
2
copies elsewhere
how many repositories repackaged it
94770
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/DietrichGebert/ponytail --skill ponytail-review

The instruction itself

4 sections, as written by the author

Review diffs for unnecessary complexity. One line per finding: location, what

to cut, what replaces it. The diff's best outcome is getting shorter.

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 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.

Examples

❌ "This EmailValidator class might be more complex than necessary, have you

considered whether all these validation rules are needed at this stage?"

L12-38: stdlib: 27-line validator class. "@" in email, 1 line, real validation is the confirmation mail.

L4: native: moment.js imported for one format call. Intl.DateTimeFormat, 0 deps.

repo.py:L88: yagni: AbstractRepository with one implementation. Inline it until a second one exists.

L52-71: delete: retry wrapper around an idempotent local call. Nothing replaces it.

L30-44: shrink: manual loop builds dict. dict(zip(keys, values)), 1 line.

Scoring

End with the only metric that matters: net: -<N> lines possible.

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

Boundaries

Scope: over-engineering and complexity only. Correctness bugs, security holes,

and performance are explicitly out of scope. Route them to a normal review

pass, not this one. A single smoke test or assert-based

self-check is the ponytail minimum, not bloat, never flag it for deletion.

Does not apply the fixes, only lists them.

"stop ponytail-review" or "normal mode": revert to verbose review style.

Repackaged in 2 other repositories

same content, different owner
0xwilliamortiz/ponytail-improved open on GitHub →
google/tf-remote-vars open on GitHub →

How to use it

Copy the folder

Take dietrichgebert/ponytail-ponytail-review from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.