Conciseness

The body is mostly efficient and action-oriented (commands, quick-reference table, triage table), with only minor trimmable padding such as the repeated description line at the top and the Real-World Impact background section; this fits the score-4 anchor ('Efficient; minor instances of over-explanation that could be trimmed') rather than 5, which requires every token to earn its place.

Actionability

Copy-paste-ready commands are given per language (e.g. "uv run {baseDir}/ct_analyzer/analyzer.py --arch arm64 crypto.c"), with flags (--warnings, --func, --json, --arch, --opt-level), a prerequisites table, and a Quick Reference mapping each problem to detection instructions and fixes, matching score 5 ('Fully executable; copy-paste ready code or commands; specific examples cover the common cases').

Workflow Clarity

A clear run-then-interpret-then-verify sequence is present, and the "Verifying Results" section provides an explicit numbered feedback loop (identify secret inputs, trace data flow, document) plus a Quick Triage Questions checklist, matching score 5 ('Clear sequence with explicit validation steps; feedback loops for error recovery; checklists for complex processes').

Progressive Disclosure

The SKILL.md is a concise overview routing per-language detail to one-level-deep reference files via a clear Language Selection table (e.g. references/compiled.md, references/swift.md, references/python.md), with no nested references and easy navigation, matching score 5 ('Clear overview with well-signaled one-level-deep references; content appropriately split; easy navigation').

Specificity

Quotes "Analyze cryptographic code" and "detect operations that leak secret data through execution timing variations" — it names the domain plus one concrete detection action, but does not enumerate several distinct actions, matching the score-3 anchor ('Names domain and 1-2 concrete actions, but not comprehensive'); it falls short of score 4 which expects multiple listed actions.

Completeness

A clear 'what' is stated ("Analyze cryptographic code to detect operations that leak secret data through execution timing variations") but there is no 'Use when...' or equivalent 'when' clause, hitting the score-3 anchor ('Has a clear what but when is missing or only weakly implied'); per the rubric guideline a missing Use-when clause caps completeness at 3, so it cannot reach 4.

Trigger Term Quality

Relevant keywords present ("cryptographic code", "leak secret data", "execution timing") but the most natural trigger phrases users say — "constant-time", "timing attack", "side-channel" — are absent from the description (they appear only in the body), matching score 3 ('Some relevant keywords but missing common variations or synonyms'); not score 4 because key natural synonyms are missing.

Distinctiveness Conflict Risk

"cryptographic code" scoped to "leak secret data through execution timing variations" carves a clear, narrow niche (constant-time / timing side-channel analysis) with minimal overlap risk against other skills, matching the score-5 anchor ('Clear niche with distinct triggers; minimal conflict risk'); it is more distinct than the score-4 'mostly distinct' anchor.