Conciseness

The body is mostly lean, but the intro paragraph ('By default, a CSS change anywhere on the page can potentially affect any other element's layout...') re-explains a concept Claude already knows and is duplicated nearly verbatim in references/rule.md's 'Why It Matters'; the Code Review section also restates the description. Matches 'mostly efficient but includes some unnecessary explanation' rather than the minor-trim anchor 4.

Actionability

The Quick Reference provides concrete contain values ('contain: layout style paint', 'content-visibility: auto', 'contain: strict'), but the Fix section is vague ('Add appropriate contain values') with no selectors or CSS in the body — all executable code lives in the reference. Some concrete guidance but incomplete on its own, matching anchor 3; the high-level-only anchor 2 is too harsh given the specific values listed.

Workflow Clarity

Check/Fix/Explain/Code Review read as parallel task categories rather than a clearly sequenced workflow, and the validation checkpoint (check the rendered layout across breakpoints before proposing a fix) is stated in the description and reference but only implicit in the body. No destructive/batch cap applies; the steps are listed but checkpoints are implicit, matching anchor 3.

Progressive Disclosure

The body is a concise overview and points to exactly one well-signaled, one-level-deep reference ('For full implementation details, code examples, and framework-specific guidance, see references/rule.md'), which exists and contains the code examples, use cases, and verification steps. This matches the clear-overview-with-well-signaled-references anchor.

Specificity

The description names the domain ('Use CSS containment to limit repaint scope') and 1-2 concrete actions ('Check the rendered layout across breakpoints and interaction states before proposing a fix'), but the mid-sentence re-embedding of the rule title ('related to Use CSS containment to limit repaint scope') muddles the action statement and coverage is not comprehensive. Not score 4 because it lacks the several cleanly listed specific actions of that anchor; not score 2 because it goes beyond naming the domain.

Completeness

Both what ('Check the rendered layout across breakpoints and interaction states before proposing a fix') and when ('Use when reviewing stylesheets, component styles, and responsive behavior related to...') are explicitly present with concrete trigger phrases. Not score 5 because the duplicated title phrase inside the 'when' clause makes the trigger statement awkward and less cleanly explicit than the anchor example.

Trigger Term Quality

Good natural keyword coverage: 'stylesheets', 'component styles', 'responsive behavior', 'breakpoints', 'interaction states', 'repaint'. Missing a few natural terms users would say, such as 'reflow', 'rendering performance', or 'contain property', so it falls short of the comprehensive anchor 5.

Distinctiveness Conflict Risk

The trigger surface ('reviewing stylesheets, component styles, and responsive behavior') is broad frontend-review territory that would overlap with sibling CSS-review skills; only the embedded containment/repaint phrase distinguishes it. Somewhat specific but still overlapping, matching anchor 3 rather than the mostly-distinct anchor 4.