Conciseness

The body re-teaches concepts Claude already knows: 'Debounce: delays execution until activity stops (search inputs, form validation)' and 'High-frequency events fire hundreds of times per second, causing UI jank, excessive API calls, and poor Interaction to Next Paint (INP) scores.' The genuinely non-obvious specifics ('Use 150-300ms delay for user input, 100ms for scroll/resize', 'Clean up event listeners to prevent memory leaks') do earn their place, so this is mostly efficient with some unnecessary explanation — anchor 3 rather than 4, and well above anchor 2's pervasive padding.

Actionability

Concrete elements exist — specific delay values ('150-300ms delay for user input, 100ms for scroll/resize'), named events ('scroll, resize, input, mousemove'), and specific flagging instructions ('Flag exact imports, event handlers, runtime side effects, or blocking operations') — but the Fix directive 'Add debounce or throttle to high-frequency event handlers to limit execution rate and improve performance' is abstract, with no inline code and the pointer to the executable examples relegated to the bottom of the file. This lands at anchor 3 (some concrete guidance but incomplete) rather than 4.

Workflow Clarity

Check, Fix, Explain, and Code Review are parallel task modes rather than a sequenced workflow, and validation is only implicit — 'state how the change should be verified in the browser' — with the actual verification steps deferred to references/rule.md instead of being surfaced as checkpoints. Anchor 3 (steps listed but validation gaps, checkpoints implicit) fits; not 4 because no explicit validation sequence appears in the body, not 2 because each mode's action is clearly delineated.

Progressive Disclosure

The body is a concise, well-sectioned overview that defers implementation detail via a clearly signaled one-level-deep reference — 'For full implementation details, code examples, and framework-specific guidance, see `references/rule.md`' — and that file exists and appropriately contains the debounce/throttle implementations, React/Vue examples, and verification checklist. This matches anchor 5: clear overview, well-signaled single-level reference, content appropriately split.

Specificity

The description names its domain ('Debounce and throttle event handlers') and offers about two concrete actions — 'Inspect both source code and the browser execution path' — but the coverage is not comprehensive: 'reviewing scripts, client components, bundles, or runtime behavior' is an umbrella verb over objects rather than a list of specific actions. It matches anchor 3 (domain plus 1-2 concrete actions) and falls short of anchor 4, which expects several distinct specific actions such as flagging handlers, applying delays, or verifying fixes.

Completeness

Both halves are present: the 'when' is explicit and specific ('Use when reviewing scripts, client components, bundles, or runtime behavior related to Debounce and throttle event handlers') and the 'what' is stated ('Inspect both source code and the browser execution path so fixes target the real bottleneck or bug'). It sits at anchor 4 rather than 5 because the 'what' is thin — it never says what the review actually produces (e.g., flag unrate-limited handlers, apply debounce/throttle, verify in browser).

Trigger Term Quality

It contains the primary natural terms users would say — 'Debounce', 'throttle', 'event handlers' — plus useful context terms ('scripts', 'client components', 'runtime behavior'). It misses common natural variations like scroll, resize, search input, or performance/jank phrasing, so it fits anchor 4 (good coverage, a few natural terms missing) rather than anchor 5's comprehensive synonym coverage.

Distinctiveness Conflict Risk

The 'Debounce and throttle event handlers' niche is clearly distinct with a strong anchor term, but the broad framing 'reviewing scripts, client components, bundles, or runtime behavior' creates minor overlap risk with general JavaScript or performance-review skills. This matches anchor 4 (mostly distinct, minor overlap risk with closely related skills) rather than anchor 5's minimal conflict risk.