The body is lean with no padding of concepts Claude already knows; every section (baseline, loop, variant table, recursive search, promotion gate) earns its place. Not below 3 since it assumes competence and adds only domain-specific structure.

Concrete executable commands appear in the variant table ('npm run job -- --batch 500', 'npm run job -- --workers 8') plus specific phrases and an exact promotion-gate checklist. Not below 2 because the guidance is copy-paste ready rather than abstract.

An explicit 8-step loop with validation checkpoints (correctness gate, reject failing variants, rerun baseline to confirm delta) and clear promotion/stop conditions. Not below 3 since validation and feedback loops are present for batch/optimization work.

Under 50 lines, no bundle files, and well-organized into clear sections; as a simple single-purpose skill this satisfies the rubric's simple-skills note. Not below 3 because no external references are needed and structure is clean.

Lists multiple concrete actions: 'try many variants', 'run recursive optimization', 'benchmark latency/throughput/cost', 'choose the best implementation by repeated measured tests'. Not below 3 since it names several specific actions rather than a vague domain.

Explicit 'Use when' clause gives clear triggers, and the enumerated actions answer what the skill does. Not below 3 since both what and when are explicitly stated.

Natural user phrasings are well covered: 'make something faster', 'try many variants', 'recursive optimization', 'benchmark', 'choose the best implementation'. Not below 3 because these are terms users would naturally say.

The benchmark-optimization-loop niche with repeated-measured-test triggers is distinct and unlikely to fire for unrelated skills. Not below 3 because triggers are specific to optimization work.