Conciseness

The body is lean and assumes Claude's competence — it lists operating rules, I/O fields, and a single executable command without explaining what PheWAS or GRCh38 coordinates are, so every token earns its place.

Actionability

It provides a copy-paste-ready command (`echo '{...}' | python scripts/ukb_topmed_phewas.py`), concrete input field lists, and example JSON payloads, leaving no ambiguity about how to invoke the script.

Workflow Clarity

For this simple single-purpose lookup the sequence is unambiguous (resolve one input to GRCh38 → call with max_results=10 → increase only if truncated → return summary or raw path), and re-run/error handling is explicitly addressed.

Progressive Disclosure

At under 50 lines with no need for external references, the body is organized into clear sections and the References section correctly states no additional runtime references are needed; the referenced `scripts/ukb_topmed_phewas.py` is a real bundle file.

Specificity

The description names multiple concrete actions: 'Fetch compact UKB-TOPMed PheWAS summaries', 'accepting rsID, GRCh37, or GRCh38 input', and 'resolving to the required GRCh38 query', matching the top anchor that lists several specific actions.

Completeness

It states both what the skill does and an explicit 'Use when a user wants concise UKB-TOPMed association results for one variant' trigger, satisfying the what-and-when anchor at the top level.

Trigger Term Quality

It surfaces the natural terms a user of this niche would actually say — 'PheWAS', 'rsID', 'GRCh37', 'GRCh38', 'association results', 'variant' — giving good coverage rather than generic jargon.

Distinctiveness Conflict Risk

The niche (UKB-TOPMed PheWAS for single variants) is highly specific with distinct triggers, making conflict with other skills unlikely; it does not sit at score 2 because no overlap with sibling skills is apparent.