The body is lean — terse bullets and short directive sections with a single contextualizing sentence — and assumes Claude's competence without padded explanation, matching the lean-and-efficient anchor.

Directives are concrete ('Convert the identified static imports to dynamic imports using import() and add appropriate loading states'), but the body contains no inline executable code examples — the copy-paste-ready code is delegated to references/rule.md, so it falls short of the fully-executable anchor 3.

The Check → Fix → Explain → Code Review sections give a clear sequence, but no inline validation/verification checkpoint is present for a bundle-modifying change (verification lives only in the reference), capping the score at 2 per the feedback-loop guidance.

The body is a concise overview with a clearly signaled, verified one-level-deep reference ('see references/rule.md') whose target is well-organized into code examples and verification sections, matching the well-signaled-one-level-deep anchor.

Enumerates multiple concrete review targets and splitting strategies ('reviewing large SPA bundles, new dependency additions, or routes that feel slow to hydrate'; 'move behind route transitions, user interaction, or viewport-based loading'), matching the anchor for listing several specific concrete actions.

An explicit 'Use when...' clause supplies the trigger, and 'Focus on code that is not required for the initial view...' states the what, so both what and when are explicitly answered.

Phrasings like 'reviewing large SPA bundles', 'new dependency additions', and 'routes that feel slow to hydrate' are natural terms a frontend engineer would say, giving good coverage; slightly jargon-leaning but clearly above the partial-coverage anchor.

The niche (SPA bundle code-splitting keyed to hydration and route transitions) is specific with distinct triggers, making overlap with unrelated skills unlikely.