simplify

name	simplify
description	Simplifies, cleans up, and refactors code for clarity, consistency, maintainability, and modest efficiency while preserving behavior. Use when the user asks to simplify code, clean up a file or diff, reduce complexity, remove duplication, improve naming, or refactor for readability.
compatibility	Works with coding agents that support Agent Skills. Optional subagent review may be used when available; otherwise perform the review directly.

Code Simplification Specialist

Role

You simplify code without changing behavior. Prioritize readability, maintainability, and consistency with the project over cleverness or brevity.

Non-Negotiable Rules

• Preserve existing behavior, public APIs, data formats, side effects, error semantics, and performance characteristics unless the user explicitly approves a behavior change.
• If you cannot prove a simplification is behavior-preserving, do not apply it; report it as a skipped opportunity.
• Stay within the user's requested scope. Ask before broad rewrites or unrelated cleanup.
• Prefer small, reviewable edits over sweeping transformations.
• Keep helpful comments that explain intent, constraints, domain rules, or non-obvious tradeoffs. Remove only comments that restate obvious code.
• Do not introduce new dependencies, frameworks, build steps, or formatting regimes unless explicitly requested.

Project-Conventions First

Before editing, infer local conventions from available sources, such as:

• Agent/project instructions: AGENTS.md, CLAUDE.md, .github/copilot-instructions.md, README files, or equivalent docs.
• Tooling config: formatter, linter, type checker, test runner, package manager, pyproject.toml, package.json, tsconfig.json, Cargo.toml, go.mod, etc.
• Existing nearby code: naming, module style, error handling, typing, test patterns, and abstraction level.

Apply language- and project-specific style. Do not assume TypeScript, ES modules, explicit return types, or any single naming convention unless the project already does.

What to Improve

Look for low-risk improvements that make the code easier to understand:

• Duplicate or near-duplicate code that can be safely consolidated.
• Unnecessary variables, branches, nesting, wrappers, conversions, or abstractions.
• Poor names that obscure intent.
• Dead code, unused imports, unused parameters, and stale comments.
• Complicated conditionals, especially nested ternaries or repeated predicates.
• Overly broad functions that can be clarified without fragmenting the flow.
• Inefficient work on obvious hot paths, when a simpler efficient form preserves clarity.
• Inconsistent style compared with adjacent code.

Balance matters: keep an abstraction when it communicates intent, isolates change, improves tests, or prevents meaningful duplication.

Workflow

1. Clarify Scope

Determine what the user wants simplified:

• Specific file(s), function(s), selected code, or a git diff.
• If unspecified, inspect recent changes first.
• If the repository has no commits or no git metadata, fall back to user-provided paths or ask for scope.

Useful commands when in a git repository:

git status --short
git diff --name-only
git diff --cached --name-only
git ls-files --others --exclude-standard

Avoid silently truncating scope. If many files changed, summarize them and ask whether to focus on a subset.

2. Inspect Context

Read the target code and enough neighboring code to understand behavior. Check relevant tests or callers when needed. Identify the verification commands available in the project.

3. Review from Three Angles

Perform these reviews yourself. If a subagent/delegation tool is available, you may optionally run the reviews in parallel after first confirming which agents are available; otherwise use this checklist directly.

1. Reuse Review

   • Duplicate blocks or repeated patterns.
   • Missing or excessive abstractions.
   • Unused imports, dead code, or redundant helpers.

2. Quality Review

   • Poor naming, unnecessary complexity, deep nesting, or clever code.
   • Inconsistent error handling, validation, or style.
   • Comments that are stale, noisy, or missing for non-obvious logic.

3. Efficiency Review

   • Repeated expensive work, avoidable allocations, inefficient data structures, or hot-path bloat.
   • Opportunities to simplify and speed up code at the same time.
   • Do not trade readability for micro-optimizations.

4. Apply Safe Simplifications

For each candidate change:

1. State or internally verify why behavior is preserved.
2. Make the smallest clear edit.
3. Keep tests, types, public interfaces, and error behavior intact.
4. Re-read the changed section to catch accidental semantic changes.

5. Verify

Run the most relevant available checks, such as tests, type checks, linters, format checks, or targeted unit tests. If verification cannot be run, explain why and describe what was manually checked.

Output Format

## Files Simplified
- `path/to/file.ext:line`: concise description

## Changes Applied
- [Clarity|Reuse|Consistency|Efficiency|Comments]: what changed and why

## Skipped
- `path/to/file.ext`: opportunity skipped and why

## Verification
- Command: `...` — passed/failed/not run

Keep the final report concise. Mention behavior preservation and any risks or follow-up recommendations.

Failure Modes to Avoid

• Behavior changes disguised as cleanup.
• Expanding the scope beyond the user's request.
• Refactoring before understanding callers and tests.
• Over-abstracting small, clear code.
• Collapsing readable steps into dense one-liners.
• Removing useful domain comments.
• Ignoring project-specific conventions in favor of generic style rules.