Prose is mostly lean with efficient comparison tables, but contains mild padding (e.g., the definitions section and repeated restatements of "every attribute on a span is a dimension"). Not score 3 because a few passages could be tightened without losing meaning; not score 1 because it does not pad with concepts Claude already knows at length.

Offers some actionable framing ("Instrument for the questions you'll ask at 3am" and the who/what-changed/where-bottleneck attribute list), but largely describes and compares concepts rather than giving concrete, executable steps. Not score 3 because there is no copy-paste-ready or fully specific guidance; not score 1 because the three-questions list and pointers to attribute catalogs are concrete enough to act on.

The Core Analysis Loop is clearly sequenced (Define → Visualize → Investigate → Evaluate), but the steps lack explicit validation/checkpoint guidance and the "Evaluate" step's confirmation loop is implicit. Not score 3 because there are no explicit validation checkpoints or error-recovery feedback loops; not score 1 because a real, ordered sequence is present.

Body is a clear overview that points one level deep to a verified real reference file (references/events-vs-metrics-vs-logs.md) and signals sibling skills, with no nested reference chains. Not score 2 because references are clearly signaled and the detailed code examples are appropriately split out of the overview.

Lists multiple specific concrete concepts ("wide events, high cardinality, the core analysis loop, events vs metrics vs logs") rather than vague language; for a conceptual skill this is as concrete as the anchor's "multiple specific concrete actions". Not score 2 because it goes beyond naming a domain — it enumerates several distinct conceptual actions.

Explicitly answers what ("First principles behind observability... Grounds recommendations in first principles rather than tool-specific how-to") and when ("Trigger phrases: ... or any conceptual question about observability"). Not score 2 because the "when" is explicit via the trigger-phrase clause, not merely implied.

Provides ~13 natural trigger phrases users would actually say ("what is observability", "why Honeycomb", "events vs metrics vs logs", "observability vs monitoring", "what is dimensionality") with broad coverage and variations. Not score 2 because it covers many common phrasings rather than only some relevant keywords.

Occupies a clear conceptual niche and explicitly defers tool-specific work to other skills (otel-instrumentation, query-patterns), with distinct triggers unlikely to fire for the wrong skill. Not score 2 because the boundary against sibling skills is drawn explicitly.