Conciseness

Nearly all content is non-obvious project knowledge (bench harness internals, trace-parsing recipes, the Immer scaling wall, `recording: "silent"` semantics) with no padding about concepts Claude already knows. Minor trimming opportunities exist: the bench run command appears three times ("The Benchmark System", "Step 1: Baseline", "Node CPU profiles") and the OOM-heap and "bench omits React" warnings are each stated twice. Anchor 4 rather than 5 because of that repeated material; not 3 because nothing is generic or over-explained.

Actionability

Copy-paste-ready throughout: exact commands ("GRIDA_PERF=1 GRIDA_PERF_CPUPROFILE=1 pnpm vitest run editor/grida-canvas/__tests__/bench/perf-editor.test.ts", "NODE_OPTIONS=\"--max-old-space-size=8192\"", "--cpu-prof --cpu-prof-interval=100"), executable code for instrumentation (perf.start with try/finally, perf.measure) and a runnable Python trace parser, plus concrete grep discovery queries. A single hedge ("runAndTime() (or similar)") aside, the common cases are fully covered — anchor 5 rather than 4.

Workflow Clarity

"The Verification Workflow" sequences Baseline → Implement → Measure → Regression check → Accept/iterate with explicit validation checkpoints (headless tests, "pnpm turbo typecheck --filter=editor", "Non-target operations within 10% of baseline") and an accept-criteria table. The tool-selection decision rules add an upfront decision workflow, and the regression step is a genuine feedback loop. Anchor 5: explicit validation steps, error-recovery guidance, and a checklist.

Progressive Disclosure

In-file structure is good (clear headers, cross-references like "see 'Pick your measurement tool' above") and it correctly delegates volatile detail to repo files ("The bench README has the authoritative catalog — read it there") and to the sibling render-perf skill. However, no references/, scripts/, or assets/ bundle exists and the ~490-line body inlines whole topics that belong in separate files — the browser-trace parsing guide, the PerfObserver API reference, and the Node CPU profile section could each be a one-level-deep reference. That matches anchor 3 (content that should be separate is inline), not 4 (no bundle references exist at all), and not 2 (section structure and navigation are clear, not minimal).

Specificity

"Guides performance investigation, benchmarking, and optimization of the Grida Canvas web editor (TypeScript reducer, Immer, React hooks)" names the domain plus multiple concrete actions — profiling dispatch cost, diagnosing slow interactions, writing/running benchmarks, instrumenting with PerfObserver, optimizing the state pipeline. Coverage is comprehensive with no vague filler; not a 4 because there are no meaningful gaps in the action list.

Completeness

Explicitly answers both what ("Guides performance investigation, benchmarking, and optimization...") and when ("Use when profiling reducer dispatch cost, diagnosing slow interactions..., instrumenting with PerfObserver, or optimizing the JS-side state management pipeline"). The 'when' clause lists five concrete trigger phrases; not a 4 because the 'when' could not be more explicit or specific.

Trigger Term Quality

Natural user phrases are present: "diagnosing slow interactions (drag, resize, color change)", "profiling reducer dispatch cost", "writing or running editor benchmarks", "optimizing". A few natural terms a user would say are missing — "laggy", "slow editor", "frame drops", "fps" — and no synonyms or file extensions beyond PerfObserver, so it fits anchor 4 (good coverage, a few natural terms missing) rather than 5 (comprehensive synonyms and extensions).

Distinctiveness Conflict Risk

Anchored to a clear niche (Grida Canvas editor, TypeScript reducer, Immer, PerfObserver) and bounds itself to the "JS-side state management pipeline", so it would not trigger for generic perf work or the companion Rust render-perf skill. Minimal conflict risk; not a 4 because the triggers are product-specific and unambiguous.