The body is dense with actionable specifics — exact mask stops, easing values, and complete executable HTML/CSS/JS — without explaining basic concepts Claude already knows; each section earns its place addressing genuine edge cases. Not 2 because it avoids padded explanation despite being long, and there is no level above.

Provides complete, copy-paste-ready HTML markup, CSS mask rules, and a full JS init function with concrete values (radii, easing factors, mask alphas); not 2 because it is executable rather than pseudocode with no key details missing.

The 'Core Contract' is a clearly numbered 7-step sequence and 'Quick Checks' act as an explicit validation checklist covering alignment, idle-loop cleanup, and fallback states; not 2 because checkpoints are explicit rather than implicit, and not capped at 2 since this is not a destructive/batch operation requiring a validate→fix→retry loop.

No bundle files exist, so the self-contained single file is organized into clear, well-signaled sections (Core Contract, Motion Defaults, Markup, CSS Mask, Eased Pointer Tracking, Touch/Accessibility, Performance, Quick Checks) with no nested references; per the simple-skill guideline, well-organized sections with no external-reference need can score 3.

Quotes concrete actions — 'Build cursor-following spotlight reveals that expose a second aligned image through a soft radial mask' — listing multiple specific behaviors (build, expose via mask, follow pointer, ease) rather than vague language; not below 3 since it lists multiple concrete actions, and there is no level above.

Explicitly answers both what ('Build cursor-following spotlight reveals... soft radial mask') and when via an explicit 'Use for...' clause with multiple triggers; not 2 because the 'when' is explicit, not merely implied.

Provides broad natural-term coverage — 'hover-to-color, before-and-after, x-ray, material, texture, product-detail, and illustrated hero effects' — terms users would actually say; not 2 because coverage is comprehensive rather than partial.

A very specific niche — cursor-following spotlight reveals through a radial mask with dual aligned images — with distinct triggers that are unlikely to fire for unrelated skills; not 2 because it does not plausibly overlap with general image or animation skills.