Conciseness

Largely efficient: dense bullets, bolded project-specific numbers ('~15-17% pass/fail flip rate', '3.4x wall-clock speedup', '23 of 24 cases inconclusive') that Claude could not know, with no explanation of generic concepts. Not 5 because of minor repetition — concurrency guidance appears in both sections 2 and 5, and section 5's closing line restates earlier bullets.

Actionability

Fully executable throughout: copy-paste CLI commands with all flags ('--trials 5 --concurrency 4 --compare-baseline "$BASELINE_JSON"'), concrete recommended trial counts per lane, explicit practical cutoffs ('0.05 score delta'), and a complete A/B loop including jq extraction of the baseline path. Covers prompt, execution, dogfood, and full-comparison cases.

Workflow Clarity

The before/after workflow is a clearly numbered 5-step sequence with explicit checkpoints (save the baseline report.json path, run candidate with --compare-baseline, read verdicts), plus feedback loops: interpretation rules ('do not call something better just because the mean moved'), the inconclusive-is-healthy default, and 'add more trials before making a claim' when results are noise-dominated. Section 7 adds a rerun-'npm run test' validation step for new cases.

Progressive Disclosure

No bundle files exist; the skill is a single well-organized file with ten clearly numbered sections and no nested or dangling references. Not 5 because at ~205 lines some reference-grade material (the six-command quick-reference cookbook in section 6, the authoring API in section 7) is inlined where a one-level-deep references file would keep the overview leaner.

Specificity

Names the domain ('agent-tty evals') and several concrete capabilities: 'trials, parallelism, and A/B comparison', 'non-determinism baseline, recommended sample sizes, and result interpretation' — six specific items with minor gaps. Not 5 because the 'Guide for running...' framing is coverage-list rather than a comprehensive verb-led action list; not 3 because it far exceeds 1-2 concrete actions.

Completeness

The 'what' is clear (running statistically meaningful evals with trials, parallelism, A/B comparison), but there is no 'Use when...' clause or equivalent explicit trigger guidance, which caps completeness at 3 per the judging guidelines. Not 2 because the 'what' half is concrete and multi-part.

Trigger Term Quality

Good natural keyword coverage for the domain: 'evals', 'trials', 'A/B comparison', 'baseline', 'sample sizes' — phrases a user running evals would plausibly say. Not 5 because common variations like 'evaluate a skill change', 'benchmark', 'did my prompt change help', or flag/command names are missing.

Distinctiveness Conflict Risk

Scoped to a specific niche ('statistically meaningful agent-tty evals', 'trials', 'paired baseline comparison') making it mostly distinct from generic eval or testing skills. Not 5 because without explicit trigger phrases, generic requests about 'evaluating' or 'testing a change' could still pull it in over related skills.