The body is lean for its scope: it assumes Claude's competence, contains no beginner-concept padding (no "what a profiler is"), and every section (consent gate, support matrix, error table) earns its place with actionable detail.

Guidance is fully executable: an intent-to-command mapping table and concrete invocations like `xcprof record --preset cpu --attach '<app>' --time-limit 10s` and `xcprof analyze "<trace>" --json` are copy-paste ready.

A clear four-step sequence (target, record, analyze, report) is paired with explicit validation checkpoints (the support-matrix honesty gate, the consent gate, an error-handling table with fixes) and feedback loops (hang-window re-scope, re-record with the right preset).

The single-file skill is well organized into focused sections, and external references (xcprof-ref, trace-comparison, xctrace-ref, etc.) are collected one level deep in a clearly signaled Related section; no bundle files exist to verify, so structure alone satisfies the simple-skill guidance.

Three concrete capabilities are named explicitly: "automated performance profiling, headless Instruments analysis, or CLI-based trace collection", matching the multiple-specific-actions anchor rather than the score-2 single-domain phrasing.

The "Use when the user wants..." clause answers WHEN explicitly, but WHAT is only folded into the trigger list rather than stated separately; the score-3 anchor distinctly separates the action list from the Use-when clause.

The terms a developer profiling Apple apps would naturally say are present ("performance profiling", "Instruments analysis", "trace collection"), giving good coverage rather than only jargon or a single generic keyword.

The niche is sharply scoped to Apple Instruments/headless performance tracing with distinct triggers, so it is unlikely to fire for unrelated skills.