Conciseness

The 79-line body is dense and operative throughout: it never explains concepts Claude already knows (no 'what is Svelte/$effect' padding), and every caveat — such as rule 4's untrack exception and rule 6's wrapper escape — is project policy that earns its tokens. It matches the anchor 'Lean and efficient; assumes Claude's competence; every token earns its place' rather than anchor 4, since no section could be trimmed without losing operative guidance.

Actionability

Although code-free, the guidance is fully concrete: it names exact APIs ($derived, $effect, untrack, onMount, onDestroy), gives a worked example ('handle a new notification in the notification-update handler, rather than watching notification state with $effect'), and specifies the findings format (file, line, rule, consequence, severity order). Per the rubric's code_vs_instruction_skills note, absence of code is not penalized when guidance is this actionable.

Workflow Clarity

A clear sequence is stated up front (review the scope, read the frontend instructions, trace changed behavior through callers, apply the rules before declaring the review complete), with explicit checkpoints — 'Review each new or changed $effect, untrack, and lifecycle hook explicitly' and 'Check findings against the user's requirements' — plus conditional branches ('If there are no findings, state the reviewed scope') and a mandated report of checks run and remaining gaps. It fits the anchor-5 'explicit validation steps and checklists' better than anchor 4, which requires a validation gap that is absent here.

Progressive Disclosure

The body is well organized (intro, ten numbered rules, findings format) and its only references — ../../../apps/frontend/AGENTS.md and ../chatto-client-placement/SKILL.md — are clearly signaled, one level deep, and each delegates a well-defined concern. No inline content belongs in a separate file (the rules are the operative runtime content), so it matches the anchor for appropriate splitting and easy navigation.

Specificity

'Review Chatto frontend implementation quality, including Svelte reactivity and lifecycle, component boundaries, design-system reuse, and unnecessary complexity' names the domain plus four concrete review areas, but rests on a single action verb ('Review') rather than the multiple distinct actions of the anchor-5 example ('extract, fill, merge, convert'). It is above anchor 3, which covers only 1–2 concrete actions.

Completeness

It explicitly answers both questions: the 'what' lists four concrete capability areas, and the 'when' is concrete and trigger-phrased — 'Use for every review that includes apps/frontend, including self-review, branch or PR review, and frontend architecture review.' This matches the anchor-5 example structure exactly.

Trigger Term Quality

Natural terms users would actually say are well covered — 'frontend', 'Svelte', 'review', 'PR', 'branch', 'self-review', 'component', 'design-system', plus the path trigger 'apps/frontend'. It falls short of anchor 5, which expects synonyms and file-style triggers (e.g. '.svelte files', 'UI review') that are absent.

Distinctiveness Conflict Risk

The 'Chatto' product name and the apps/frontend path scoping give the skill a clear niche with distinct triggers, leaving minimal overlap risk even against a general code-review skill (which the body explicitly defers to). This matches the anchor 'Clear niche with distinct triggers; minimal conflict risk'.