Conciseness

The body is lean throughout: it never explains what FHIR or terminology servers are, and every section (four operations, thin client, hand-off, edge cases) adds non-obvious domain knowledge such as ECL implicit value sets, pagination with count/offset, version pinning, and PHI/licensing constraints. Not 4: there is no identifiable passage that could be trimmed without losing operational value.

Actionability

The $validate-code and $expand curl examples and the TxClient.validate_code path are concrete and executable, but the "$lookup and $translate" section is shorthand ("POST [tx]/CodeSystem/$lookup { url=http://loinc.org, code=4548-4 }") rather than runnable code, and TxClient implements only validate_code despite the skill covering four operations. Mostly executable with minor gaps — anchor 4, not 5.

Workflow Clarity

The span-to-coded-concept flow is clearly sequenced (entity span + candidate code -> $validate-code -> only-if-valid coding/codeable_concept -> export) with an explicit validation gate in code ("Ground an OpenMed span only if the code validates") and a defined error-recovery path (emit text-only CodeableConcept and flag via OperationOutcomeIssue severity=warning). Validation checkpoint and failure handling are both explicit, matching the top anchor.

Progressive Disclosure

Sections are well-organized and clearly signaled (When to use, the four operations, hand-off, edge cases, standards links), but the entire ~160-line skill is inlined in SKILL.md with no bundle files (references/, scripts/, assets/ are absent). That is acceptable for a thin-client skill yet leaves bulk material like the full client or operation details inline rather than split out — good structure with minor organization gaps, anchor 4 rather than 5.

Specificity

"Call a user-supplied FHIR terminology server ($validate-code, $expand, $lookup, $translate) to validate and expand clinical codes" plus "ValueSet $expand with filters/ECL, CodeSystem $lookup, ConceptMap $translate" lists multiple specific concrete actions with comprehensive coverage of the four FHIR operations. It stays in third person ("Call", "Covers") and adds no padding.

Completeness

Both "what" (call a user-supplied terminology server; validate and expand clinical codes; thin local client; specific servers) and "when" ("Use as the grounding step ... when the user mentions terminology server, $validate-code, ...") are explicit with concrete trigger phrases. The 'when' clause is explicit and specific, matching the top anchor.

Trigger Term Quality

"terminology server, $validate-code, $expand, ValueSet, ECL, SNOMED/RxNorm/LOINC lookups, or code validation" covers the natural terms a user would say in this domain, including operation names, resource names, vocabulary names, and the plain-English phrase "code validation". Not below 5: no relevant synonym family is missing for this niche.

Distinctiveness Conflict Risk

The FHIR terminology niche ($validate-code/$expand/$lookup/$translate, Ontoserver/HAPI/tx.fhir.org, OpenMed grounding step) is highly distinctive with operation-name triggers unlikely to appear in other skills. Only "code validation" is mildly generic, but it is anchored in a strongly differentiated context — minimal conflict risk, so 5 rather than 4.