| name | code-reviewer |
| description | Use this skill when reviewing production code for dead code, duplication, unnecessary complexity, and non-idiomatic patterns. Use after implementing a feature, after refactors, or whenever code quality feedback is requested. |
| version | 0.1.0 |
Code Reviewer
Purpose
Provide direct, actionable code-quality review focused on maintainability, simplicity, and idiomatic style.
What to Look For
1. Dead Code
- Unused functions, methods, classes, variables, imports
- Unreachable branches and redundant conditionals
- Commented-out code that should be deleted
- Legacy paths or feature flags that are never used
2. Duplication
- Copy-pasted logic with small variations
- Repeated constants and magic values
- Near-duplicate blocks that should be shared
- Cases where DRY improves clarity without over-abstraction
3. Unnecessary Complexity (Over-Engineering)
- Over-engineered abstractions and indirection
- Premature generalization or pattern cargo-culting
- Abstractions with a single implementation, config nobody sets, layers with one caller (YAGNI)
- Hand-rolled code the standard library already ships
- Dependencies or code doing what the platform/language already does natively
- Speculative features and dead flexibility kept "for later"
- Functions/classes with too many responsibilities
- Clever code that hurts readability
4. Idiomatic and Functional Improvements
- Use language/framework conventions
- Prefer standard library over custom utility code
- Suggest pure functions, composition, immutability when appropriate
- Favor clear control flow (early returns, reduced nesting)
Review Process
- Scan for obvious issues (dead code, duplicate blocks)
- Evaluate architecture for unnecessary complexity
- Check language/framework idiomaticity
- Propose simplifications with concrete alternatives
- Prioritize by impact
Output Format
Use this structure:
Critical Issues
Problems that materially harm correctness or maintainability.
Recommended Changes
Improvements that would significantly improve quality.
Suggestions
Minor cleanups and idiomatic refinements.
For each finding:
- Quote the specific code
- Explain why it is a problem
- Propose a concrete fix
- Note the principle being applied
Related
For build-time discipline (writing the simplest thing that works), pair this
with the ponytail skill. The over-engineering checks above are the review-time
mirror of that ladder: deletion is the highest-value outcome.
Principles
- Deletion is often the highest-value refactor
- Simplicity beats cleverness
- Abstractions must justify their cost
- Idiomatic code is easier to maintain
- Be specific and actionable
