Lean and efficient across ~16 lines with no padding and no explaining of concepts Claude already knows; every token earns its place, matching the lean-and-efficient anchor.

Provides concrete checklists (define trigger/owner/duration/spawn cap/cleanup; pool objects, cap particles, idempotent cleanup) but stops at what to define rather than how to implement, leaving key implementation details unspecified. It is more complete than vague-only level 1 but lacks the copy-paste-ready specifics of level 3.

The Specify -> Implement safely -> Verify sequence is clear, and Verify acts as an explicit validation checkpoint (test overlaps, multiple targets, rapid repetition, pause/resume, reduced motion; sample for warnings/draw calls/frame time), matching the clear-sequence-with-validation anchor.

Under 50 lines with no external references needed, organized into three well-labeled sections; per the simple-skill scoring note this satisfies progressive disclosure with well-organized sections alone.

Lists multiple concrete actions and effect types ("Create readable, performance-safe Three.js game visual effects" plus attacks, impacts, spell trails, particles, shaders, telegraphs), matching the multiple-specific-actions anchor rather than the domain-only level 2.

Explicitly answers both what ("Create readable, performance-safe Three.js game visual effects") and when ("Use for attacks, impacts, damage feedback...") with an explicit trigger clause, not merely implied.

Natural game-dev terms users would say (attacks, impacts, damage feedback, status effects, particles, shaders, telegraphs) are well covered; third-person voice ("Create", "Use for") is correct, so no specificity penalty applies.

Niche is narrow (Three.js game VFX) with distinct triggers unlikely to overlap with general graphics or web skills; clearly distinguishable rather than merely domain-specific.