The body is dense with non-obvious operational knowledge Claude would not know (FinnGen's rsID exception, GRCh37/GRCh38 build handling, pval:0.0 underflow, BBJ meta-analysis double-counting) and does not pad with basic explanations; nearly every token earns its place, fitting the level-3 lean-and-efficient anchor.

Provides copy-paste-ready calls with real tool names and parameters (e.g. UKBTOPMed_phewas_by_variant(rsid="rs7903146", max_pval=5e-8, limit=25), exact "10:112998590:C:T" coordinate format, burden_set="pLoF") plus a concrete report template, matching the level-3 executable-guidance anchor.

A clear 5-step sequence (decide variant/gene → parallel query → align phenotypes → judge replication → report) with explicit verification checkpoints — check af/num_cases before calling biology, verify ref/alt allele on opposite beta signs — matching the level-3 anchor for explicit validation steps.

No bundle files exist, but the single SKILL.md is well-organized into clearly signaled sections (biobank panel table, workflow, interpretation table, report structure, worked example, limitations) with no nested-reference indirection, satisfying the guideline that skills with no external references can score 3 with well-organized sections.

Names multiple concrete actions — "look up every phenotype it associates with across [four named biobanks]", "plus exome-wide gene-burden PheWAS (Genebass)", "then judge whether an association replicates across ancestries or is population-specific" — matching the level-3 anchor for multiple specific concrete actions.

Explicitly answers both what (cross-biobank PheWAS + replication judgment) and when via a clear "Use whenever the user asks..." clause with multiple triggers, satisfying the level-3 requirement for both what AND when; it is not the level-2 case where 'when' is only implied.

Quoted natural user phrasings — "what else is this variant/gene associated with", "does this association replicate in other ancestries / biobanks", "is this effect East-Asian-specific", "pleiotropy of rsXXX", "phenome scan" — give good coverage of terms a user would actually say, beyond level 2's partial coverage.

A clear niche (variant/gene → cross-ancestry phenome scan) plus explicit "NOT for... use the gwas-* skills / tooluniverse-gwas-finemapping / tooluniverse-gwas-snp-interpretation" boundaries make it unlikely to trigger for the wrong skill.