| name | simplify |
| description | Review changed code for reuse, quality, and efficiency, then fix worthwhile issues. |
Simplify: Code Review and Cleanup
Review all changed files for reuse, quality, and efficiency. Fix any issues found.
Phase 1: Identify Changes
Run diffs (or diffs --commit HEAD when you need a specific commit baseline) to see what changed. Fallback to git diff only if diffs cannot express the needed flag/output. If there are no git changes, review the most recently modified files that the user mentioned or that you edited earlier in this conversation.
Phase 2: Launch Three Review Agents in Parallel
Use the subagent tool to launch all three agents concurrently in a single call. Pass each agent the full diff so it has the complete context.
Agent 1: Code Reuse Review
For each change:
- Search for existing utilities and helpers that could replace newly written code. Use grep/search to find similar patterns elsewhere in the codebase — common locations are utility directories, shared modules, and files adjacent to the changed ones.
- Flag any new function that duplicates existing functionality. Suggest the existing function to use instead.
- Flag any inline logic that could use an existing utility — hand-rolled string manipulation, manual path handling, custom environment checks, ad-hoc type guards, and similar patterns are common candidates.
Agent 2: Code Quality Review
Review the same changes for hacky patterns:
- Redundant state: state that duplicates existing state, cached values that could be derived, observers/effects that could be direct calls
- Parameter sprawl: adding new parameters to a function instead of generalizing or restructuring existing ones
- Copy-paste with slight variation: near-duplicate code blocks that should be unified with a shared abstraction
- Leaky abstractions: exposing internal details that should be encapsulated, or breaking existing abstraction boundaries
- Stringly-typed code: using raw strings where constants, enums (string unions), or branded types already exist in the codebase
Agent 3: Efficiency Review
Review the same changes for efficiency:
- Unnecessary work: redundant computations, repeated file reads, duplicate network/API calls, N+1 patterns
- Missed concurrency: independent operations run sequentially when they could run in parallel
- Hot-path bloat: new blocking work added to startup or per-request/per-render hot paths
- Unnecessary existence checks: pre-checking file/resource existence before operating (TOCTOU anti-pattern) — operate directly and handle the error
- Memory: unbounded data structures, missing cleanup, event listener leaks
- Overly broad operations: reading entire files when only a portion is needed, loading all items when filtering for one
Phase 3: Fix Issues
Wait for all three agents to complete. Aggregate their findings and fix each issue directly. If a finding is a false positive or not worth addressing, note it and move on — do not argue with the finding, just skip it.
When done, briefly summarize what was fixed (or confirm the code was already clean).
