Conciseness

The body is dense and instructional with no tutorials on concepts Claude already knows — sections like the Error Handling table and Instructions carry concrete detail ('Retry with exponential backoff; deactivate subscription after 5 consecutive failures') — but the Overview ('Build event-driven APIs using outbound webhooks, Server-Sent Events (SSE), and message broker integration. Implement event emission from API mutations, event schema registry, subscriber management...') substantially restates the description and Instructions, and the Prerequisites list could be tightened. This matches anchor 4, 'Efficient; minor instances of over-explanation that could be trimmed,' rather than 5 because of that redundancy.

Actionability

Guidance is highly concrete — naming convention ('resource.action' with e.g. 'order.created'), enumerated schema fields, exact endpoints ('POST /webhooks', 'GET /events/stream'), HMAC-SHA256 signing, a full backoff schedule (1min, 5min, 30min, 2hr, 24hr), and heartbeat details (':keepalive\n\n' every 15s). Per the scoring note an instruction-only skill is not penalized for lacking code, but it stops short of copy-paste-ready snippets, so anchor 4 ('Mostly executable guidance... minor gaps') fits better than 5.

Workflow Clarity

The 8 numbered steps form a coherent, logical sequence (identify mutations → schemas → emitter → subscription API → delivery → SSE → DLQ → integration tests). It is not a 5 because validation appears only as a terminal test-writing step rather than explicit checkpoints between steps (e.g., verify the emitter publishes before building delivery on top of it); not a 3 since step 8 does mandate integration tests covering each subsystem.

Progressive Disclosure

The body is a clear overview with well-signaled, one-level-deep references — links to references/implementation.md ('full implementation guide'), references/errors.md ('comprehensive error patterns'), and references/examples.md ('additional examples'), all of which exist in the bundle and contain no nested references. This matches the anchor 'Clear overview with well-signaled one-level-deep references; content appropriately split; easy navigation'.

Specificity

The description names the domain ('event-driven APIs') and several concrete capabilities ('webhooks, Server-Sent Events, and real-time notifications'), matching the anchor 'Lists several specific actions; minor gaps in coverage'. It falls short of a 5 because delivery guarantees, subscriber management, and event schema work mentioned only in the body are not reflected, and the items listed are technologies rather than fully enumerated actions.

Completeness

It explicitly answers 'what' ('Build event-driven APIs with webhooks, Server-Sent Events, and real-time notifications') and 'when' ('Use when building event-driven API architectures'), then adds concrete trigger phrases, matching the anchor 'Clearly and explicitly answers both what AND when with concrete trigger phrases'. A 4 would require the 'when' to be only implicit or less specific; here it is explicit and paired with trigger examples.

Trigger Term Quality

Trigger phrases 'add webhooks', 'implement events', 'create event-driven API' are natural phrasings a user would say, giving good keyword coverage. It is not a 5 because common variations such as 'SSE', 'streaming', 'push notifications', or 'pub/sub' are absent as trigger terms.

Distinctiveness Conflict Risk

The webhook/SSE/event-emission niche is mostly distinct with clear triggers, but phrases like 'add webhooks' or 'implement events' could overlap with a dedicated webhooks-only or pub/sub skill, matching 'Mostly distinct; minor overlap risk with closely related skills' rather than the clear-niche 5.