performance-hint

name	Performance Hint
description	Notices performance issues when viewing code with nested loops, database queries in loops, inefficient algorithms, or missing caching. Use when user shows code that might have O(n²) complexity, N+1 queries, or obvious performance bottlenecks.
allowed-tools	Read

Performance Hint

Lightweight performance awareness for conversations. Provides quick hints about potential bottlenecks without deep analysis.

When to activate

Activate when you notice in code being discussed:

• Nested loops (O(n²) or worse)
• Database queries inside loops (N+1 problem)
• Sorting or filtering inside loops
• Sequential API calls that could be parallel
• Large arrays without pagination
• Missing memoization for expensive operations
• Event listeners without cleanup

What to do

Briefly mention the issue in 1-2 sentences, then suggest running a command:

Example responses:

"This nested loop creates O(n²) complexity on lines 45-52.
Run `/review src/utils.js` to check for performance optimizations."

"I see a query inside a loop (N+1 problem) on line 28. This will make 100+ database calls.
Run `/deep-review` to analyze performance and get optimization suggestions."

"These API calls are sequential (lines 15-18) but could run in parallel with Promise.all.
Run `/quick-check src/api/` for performance check."

Important rules

• ❌ Do NOT perform full complexity analysis
• ❌ Do NOT benchmark or profile code
• ✅ Only mention obvious issues in current conversation
• ✅ Keep hints brief (1-2 sentences)
• ✅ Always suggest a command for detailed analysis
• ✅ Focus on impactful optimizations, not micro-optimizations

Red flags to watch for

Algorithm complexity:

• Nested loops, especially with array methods like .find() or .filter()
• Sorting inside loops

Database:

• Queries in for/forEach loops
• Missing include or eager loading
• No pagination on .findAll()

Memory:

• Event listeners without removal
• Timers/intervals not cleared
• Large objects in closures

Network:

• Multiple await calls that could use Promise.all
• No request debouncing
• Fetching entire datasets

Commands to suggest

• /quick-check - for fast performance scan
• /review [file] - for specific file analysis
• /deep-review - for comprehensive performance review with optimization strategies

This is a hint tool, not a replacement for proper performance profiling.