docs(skill): clarify performance review triggers

shared/skills/reviews/performance-review/SKILL.md

@@ -1,10 +1,18 @@
 ---
 name: performance-review
-description: Review changes for meaningful performance risks.
+description: Use when evaluating a code change for likely latency, throughput, memory, allocation, or resource-use regressions; distinguish measurements from estimates.
 ---
 
 # Performance Review
 
-Identify measurable or plausible bottlenecks in the changed paths.
+Use when reviewing a change for meaningful latency, throughput, memory, or resource-use risk.
 
-Return evidence, expected impact, and proportionate recommendations. Avoid speculative optimization.
+## Review
+
+1. Identify the changed execution paths and their expected frequency, input size, and concurrency.
+2. Trace expensive work such as repeated I/O, network calls, database round trips, allocations, serialization, locks, and scans.
+3. Estimate algorithmic cost and resource growth with realistic data sizes. Separate measured results from reasoned estimates.
+4. Check whether a proposed cache, parallelism, or batching change preserves invalidation, ordering, cancellation, and failure behavior.
+5. Recommend a benchmark or profiler only when it can answer a concrete uncertainty. Avoid micro-optimizations without a plausible user impact.
+
+Report the affected path, evidence, likely impact, and smallest useful correction or measurement. Do not present theoretical concerns as confirmed regressions.