Ponytail Review

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

0. Invocation Guard

Check the initiating user prompt:

• If this turn was NOT explicitly initiated by /ponytail-review, ABORT this workflow immediately and proceed with standard review or discussion without applying ponytail-review constraints.
• Do NOT auto-trigger for informal requests like "what can we delete", "is this over-engineered", or general diff checks unless /ponytail-review is explicitly typed.
• Single-turn scope only: applies strictly to the turn where /ponytail-review is explicitly invoked.

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. Applies strictly to the turn explicitly invoked via /ponytail-review.