Conciseness

The body is lean with no concept explanations and every section is operational ('Operating rules', 'Input', 'Output', 'Execution'). Minor redundancy could be trimmed: the 'Execution' bash example duplicates one of the 'Common EVA patterns' JSON examples almost verbatim, and the full optional-field list arguably belongs in the script's own interface docs. This fits 'efficient; minor instances that could be trimmed' rather than 'every token earns its place'.

Actionability

Guidance is fully executable and copy-paste ready: an exact base_url, a ready-to-run bash pipe ('echo ... | python scripts/rest_request.py'), two concrete JSON request patterns, and precise success/failure output contracts ('Failure returns ok=false with error.code and error.message'). It covers the common cases completely.

Workflow Clarity

This is a simple, single-purpose skill (run one script with one JSON input) and the single action is unambiguous: the exact command, input format, and output interpretation are all specified. The explicit failure contract (ok=false with error.code/error.message) provides the feedback signal for error recovery, and no destructive or batch operations are involved that would require additional validation checkpoints.

Progressive Disclosure

At ~37 lines with a single bundle script, the skill needs no external reference files and says so explicitly ('No additional runtime references are required; keep the import package limited to this file and scripts/rest_request.py'), and that script exists in the bundle. Content is appropriately split (SKILL.md as the interface, rest_request.py as the implementation) with well-organized sections and no nested references.

Specificity

The description names the domain ('EVA REST requests') and two concrete actions ('species metadata' and 'archived variant lookups'), which matches the anchor for naming a domain with 1-2 concrete actions but not comprehensive coverage. It does not list several specific actions (e.g., region queries, filters, assembly lookups) needed for a 4.

Completeness

Both 'what' ('Submit compact EVA REST requests for species metadata and archived variant lookups') and 'when' ('Use when a user wants concise European Variation Archive summaries') are explicitly present. The 'when' clause is narrower than the 'what' — it only covers 'concise summaries' and not broader variant/species data requests — so it does not fully meet the 'concrete trigger phrases covering the use cases' bar for a 5.

Trigger Term Quality

Good keyword coverage including both the acronym ('EVA') and the full name ('European Variation Archive'), plus natural terms like 'species metadata', 'variant lookups', and 'summaries'. A few natural synonyms users might say (e.g., 'rsID', 'genomic variants', 'dbSNP-style lookups') are missing, keeping it below comprehensive.

Distinctiveness Conflict Risk

The European Variation Archive is a clear niche with distinct triggers (EVA, European Variation Archive, species metadata, archived variants); it is unlikely to trigger for the wrong skill. Third-person voice ('Submit... requests') is used correctly, so no voice penalty applies.