Conciseness

Five dense rule bullets under a single '## Core Rules' heading with zero padding and no re-explanation of concepts Claude already knows (no 'what is event sourcing' filler). Every token earns its place, matching anchor 5.

Actionability

The rules are directive and specific ("Durable domain facts go into `EVT`", "must wait for the local projector(s) that serve the next read path"), but key executable details are missing: no concrete EVT subject or aggregate-lane naming example, and no concrete mechanism for the projector wait or JetStream OCC usage. This fits anchor 3 ('some concrete guidance but incomplete... missing key details') better than anchor 4, which expects mostly executable guidance.

Workflow Clarity

As a simple, under-50-line rules skill the simple-skill exception applies, and each rule is unambiguous. However, the rules are presented as flat invariants without an application order (e.g., how to sequence them when reviewing a change), leaving minor gaps versus anchor 5.

Progressive Disclosure

The body is under 50 lines, needs no external references, and consists of one well-organized section. Per the rubric guideline for simple skills, this scores 5 with just well-organized sections.

Specificity

The description enumerates concrete actions ("designing, implementing, reviewing, debugging, or documenting") alongside specific domain objects ("EVT subjects, aggregate boundaries, Services, projections, optimistic concurrency control"), giving several specific capabilities. It stops short of 5 because the verbs are generic — the specificity comes from the noun list rather than per-task concrete actions.

Completeness

The 'when' is fully explicit ("Use when designing, implementing, reviewing, debugging, or documenting Chatto event-sourced domain behavior..."), but the 'what' — that the skill supplies core invariants governing EVT usage — is only implied by the topic list. This matches anchor 4 (both present, one less explicit) rather than 5, and is clearly above anchor 3 since the when-clause is comprehensive, not weakly implied.

Trigger Term Quality

Natural domain keywords are well covered ("event-sourced", "aggregate boundaries", "projections", "optimistic concurrency control", "read-your-writes", "replay compatibility", "rollback"), which a user in this domain would actually say. A few natural synonyms are missing (e.g., "event store", "domain events", "projection rebuild"), keeping it below the comprehensive anchor 5.

Distinctiveness Conflict Risk

A clear niche ("Chatto event-sourced domain behavior") with distinctive technical triggers (EVT subjects, OCC, read-your-writes, replay compatibility) that are unlikely to collide with other skills. Minimal conflict risk, matching anchor 5.