Conciseness

The body does not explain concepts Claude already knows, but it is noticeably repetitive: the dependency/forbidden-module rules of Step 5 are restated nearly verbatim in Hard Rules 16-19, the Dataset Disclaimer appears both in Section D and Hard Rule 22, Step 4.5 citation rules repeat in Section I and Hard Rules 11-13, and Section J's requirements repeat in Hard Rule 23. This matches anchor 3 ('mostly efficient but... could be tightened') rather than 2, since the padding is rule duplication rather than concept explanation or fluffy prose.

Actionability

Concrete, specific guidance throughout: an exact input format with worked examples, an exact out-of-scope redirect script, config comparison tables, explicit dependency formulas (e.g., 'disease definition + biomarker formula + adjusted logistic association + RCS'), a verbatim disclaimer line, and exact output section categories I1-I4 with fallback phrases like 'no directly verified reference identified yet'. It falls short of anchor 5 only because some executable detail is deferred without inline summary (e.g., Step 6 mandates 'include all 8 fields' but never names the 8 fields, and literature retrieval steps depend on unspecified search tooling) — minor gaps, matching anchor 4.

Workflow Clarity

The 7 steps are explicitly ordered ('always run in order') with a mandatory validation checkpoint before output (Step 5 'Dependency Consistency Check (mandatory before output)') and a feedback loop ('If any dependency inconsistency is found, revise the plan before outputting'). Scope rejection is scripted, defaults are stated ('recommend Standard as primary'), and the output contract is enumerated as mandatory sections A-J. This matches anchor 5: clear sequence, explicit validation, error-recovery loop, and checklists.

Progressive Disclosure

The body is an orchestrating overview that delegates detail to eight well-labeled, one-level-deep reference files, each cited with a clear signal of what it contains ('→ Detailed pattern logic: [references/study-patterns.md]', '→ 8-field template + module library: [references/workflow-step-template.md]', etc.), and all eight referenced paths exist in references/. Navigation is easy and nothing is nested two levels deep, matching anchor 5.

Specificity

The description lists multiple concrete actions and outputs: 'Generates complete NHANES-style cross-sectional epidemiology + retrospective clinical validation research designs', 'always outputs four workload configs (Lite / Standard / Advanced / Publication+) with recommended primary plan, step-by-step workflow, figure plan, validation strategy, minimal executable version, publication upgrade path'. Coverage of what the skill produces is comprehensive and concrete, matching the score-5 anchor; it is not the level-4 anchor because there are no meaningful gaps in the enumerated capabilities.

Completeness

Both 'what' and 'when' are explicit and concrete: what — 'Generates complete... research designs from a user-provided disease and biomarker direction' with the five study patterns and four configs; when — 'Always use this skill whenever a user wants to design, plan, or build a population-level biomarker association study using NHANES or similar survey datasets, especially when...'. This matches the score-5 anchor with a clear trigger clause; it is not below 5 because the 'when' clause is explicit with concrete triggering conditions rather than weakly implied.

Trigger Term Quality

Good keyword coverage with natural terms users would say: 'design, plan, or build a population-level biomarker association study using NHANES', 'disease', 'biomarker', 'retrospective validation'. It misses some common natural variations (e.g., 'survey data analysis', 'prevalence study', 'cross-sectional study') and leans on technical jargon like 'restricted cubic spline analysis', so it sits between anchor 4 ('good keyword coverage; a few natural terms missing') and anchor 5 — noticeably above the midpoint but not comprehensive.

Distinctiveness Conflict Risk

The description carves out a clear niche — NHANES-style population biomarker association studies with retrospective clinical validation — with trigger terms ('NHANES', 'biomarker', 'hospital-based retrospective validation cohort') that would almost never collide with unrelated skills. It matches anchor 5 ('clear niche with distinct triggers; minimal conflict risk'); anchor 4 would require some overlap with closely related skills, which is not evident here.