comment-review

name	comment-review
description	Review comments and suggest cleanup (identify unnecessary comments, recommend improvements)
disable-model-invocation	true

Comment Review Command

Purpose

Aggressively identify and remove unnecessary comments. Code must speak for itself.

Core Principle: If code needs a comment, the code is wrong. Fix the code first.

Default Stance: When in doubt, REMOVE. Comments are technical debt.

---

User Input

$ARGUMENTS

Interpretation Priority:

1. If $ARGUMENTS provided → Follow user's request (file path, --all for entire project, etc.)
2. If empty → Check git status for uncommitted changes
3. If no changes → Review latest commit
4. Only review entire project when explicitly requested (--all or "review entire codebase")

---

Comment Principles

🚫 The Comment Problem

• Comments rot: Code changes, comments don't. Result: lies in your codebase.
• Comments mask bad code: If you need a comment, your code naming or structure is wrong.
• Comments are maintenance burden: Every comment is code you must keep synchronized.

Rule of thumb: If you're writing a comment, pause and ask "How can I eliminate this with better code?"

✅ The ONLY Legitimate Comments

These are the exclusive cases where comments are allowed. Everything else MUST be removed or refactored.

Category	Strict Criteria	Valid Examples
Public API Docs	External-facing APIs ONLY. Private code = no docs needed.	@param userId - The unique identifier (but NOT for internal helper functions)
Business Logic WHY	ONLY when domain knowledge is truly external to code	"Due to GDPR Article 17, data must be retained for 7 years"
External Dependencies	Third-party API constraints NOT under your control	"Stripe webhook retries 3 times with exponential backoff" (cite documentation URL)
Performance/Security Warnings	Counter-intuitive decisions that would surprise reviewers	"Intentionally O(n²) - n never exceeds 5 per domain requirements"
Complex Patterns	ONLY when pattern itself is inherently cryptic (rare)	Regex breakdown - but first try to simplify the regex itself
Legal/License	Copyright headers, license attribution	"MIT License", "Patent US1234567" (required by law)
TODO/FIXME	Must have: owner, ticket, deadline or removal condition	// TODO(@username): #1234 Remove after Q2 migration completes

⚠️ Business Logic Comment Rules

Single Source of Truth: Business logic explanation must exist EXACTLY ONCE.

• ❌ Banned: Same explanation scattered across multiple files
• ✅ Required: Document once in domain model/service, reference via clear function names

Example:

// ❌ BAD: Repeated everywhere
function validateAge(age) {
  // User must be 18+ per legal requirements
  return age >= 18;
}

function checkEligibility(user) {
  // User must be 18+ per legal requirements
  if (user.age < 18) return false;
}

// ✅ GOOD: Documented once, self-documenting code elsewhere
/**
 * Legal minimum age per jurisdiction requirements.
 * @see docs/compliance/age-verification.md
 */
const LEGAL_MINIMUM_AGE = 18;

function isLegalAge(age: number): boolean {
  return age >= LEGAL_MINIMUM_AGE;
}

---

Classification Criteria

❌ REMOVE (Delete Immediately)

Default assumption: Every comment should be REMOVED unless it strictly matches a legitimate case above.

Type	Example	Why It's Wrong	Fix
Code flow narration	// loop through users	Code already says this	DELETE - for (const user of users) is clear
Obvious explanation	// increment counter above counter++	Insults reader's intelligence	DELETE
Name compensation	// get user data above getData()	Function name is wrong	Rename to getUserData(), DELETE comment
WHAT instead of WHY	// validates email format	Function name should convey this	Rename to isValidEmailFormat(), DELETE
Type duplication	// returns string in TypeScript	Type system already declares this	DELETE - redundant with return type
Closing brace labels	} // end if	Indentation shows structure	DELETE - proper formatting makes this obvious
Section dividers	// ===== Validation =====	Signals function is too large	Extract to separate function, DELETE divider
Commented-out code	// oldFunction()	Git history exists for a reason	DELETE - use git log if you need old code
Outdated/lying	Comment contradicts actual code	Dangerous misinformation	DELETE IMMEDIATELY - this causes bugs
Variable restatement	const userId = 1; // user ID	Variable name already says this	DELETE
Parameter explanation	calculate(x, y) // x is width, y is height	Parameter names are wrong	Rename params to width, height, DELETE
Return value description	return result; // return the result	Meaningless tautology	DELETE
Import justification	import lodash from 'lodash'; // for utility functions	Import statement is self-explanatory	DELETE
Noise words	// Important!, // Note:, // Remember:	If it's important, code should reflect it	Fix code structure, DELETE comment
Historical commentary	// Added by John on 2023-01-15	Git blame shows this	DELETE - use git log for history
Assignment explanation	isValid = true; // set valid to true	Assignment is self-evident	DELETE
Wishful thinking	// This should work	Uncertainty has no place in production	Test it properly, then DELETE
Debugging remnants	// console.log(x);	Leftover from debugging session	DELETE - use proper debugging tools
Language feature narration	// use async/await	Code literally shows this	DELETE

Aggressive Rule: If a comment explains WHAT the code does (as opposed to WHY), it must be REMOVED. The code itself should explain WHAT.

⚠️ IMPROVE (Needs Refactoring)

Comments in this category are temporarily acceptable but must be improved. Goal: eliminate them through refactoring.

Type	Problem	Required Action
Unclear TODO	// TODO: fix later	MANDATORY: Add owner, ticket, condition
WHAT explanation	// Validates user input	Rename function to validateUserInput(), DELETE
Verbose explanation	Multi-paragraph comment block	Extract to documentation file, link in code comment
Non-standard docs	Plain comment for public API	Convert to JSDoc/TSDoc/GoDoc, or it's not an API
Scattered business logic	Same rule duplicated across files	Consolidate to ONE place, reference via naming
Missing context TODO	// FIXME: broken	Add ticket number, reproduction steps
Vague WHY	// for performance	Specify: "Cached to avoid N+1 query (see #1234)"
Missing citation	// API limit applies	Add URL: "API rate limit: 100/min (see docs.com)"

Refactoring Priority:

1. First, try to eliminate through code improvements
2. Only if impossible, improve the comment quality
3. Set deadline: Every IMPROVE comment should have a plan to become REMOVE or KEEP

✅ KEEP (Legitimately Required)

Strict criteria - ALL of these must be true:

• ✅ Matches ONE of the legitimate categories above
• ✅ Explains WHY, not WHAT
• ✅ Cannot be expressed through code alone
• ✅ Concise (ideally one line, max 3 lines)
• ✅ Synchronized with code (verified accurate)
• ✅ Single source of truth (not duplicated elsewhere)

Verification Questions (if any answer is "no", REMOVE the comment):

1. Does this explain something external to the code (business rule, API constraint, legal requirement)?
2. Would a competent developer be genuinely surprised without this comment?
3. Have I exhausted all options to express this through code structure/naming?
4. Is this the ONLY place this information exists in the codebase?

---

Workflow

1. Determine Analysis Target

git status --porcelain

Decision Tree:

1. $ARGUMENTS has specific request → Honor it
2. $ARGUMENTS empty + uncommitted changes exist → Analyze changed files via git diff
3. $ARGUMENTS empty + no changes → Analyze latest commit via git show HEAD
4. User explicitly requests entire project (--all) → Full project scan

2. Extract Comments

Language-specific patterns:

• TypeScript/JavaScript: //, /* */, /** */
• Go: //, /* */
• Python: #, """ """
• HTML/JSX: {/* */}, <!-- -->

Include with each comment:

• Comment content
• File path:line number
• Surrounding code context (±3 lines)

3. Classify with Aggressive Bias

Decision Algorithm:

For each comment:
  1. Does it match EXACTLY one of the 7 legitimate categories?
     NO → REMOVE

  2. Can the information be expressed through better code?
     YES → REMOVE (suggest refactoring)

  3. Does it explain WHAT instead of WHY?
     YES → REMOVE

  4. Is it duplicated elsewhere in the codebase?
     YES → REMOVE (consolidate to one place)

  5. Is it vague, outdated, or missing context?
     YES → IMPROVE (or REMOVE if not worth fixing)

  6. ALL checks passed?
     → KEEP (but verify it's truly necessary)

Bias toward removal: In ambiguous cases, prefer REMOVE with a refactoring suggestion.

4. Action Decision

Situation	Action
Obvious removals (commented code, trivial explanations)	REMOVE IMMEDIATELY - No discussion needed
Refactoring needed (name improvements, extractions)	SUGGEST REFACTORING - Show before/after
Unclear intent (cannot determine if legitimate)	FLAG FOR REVIEW - Ask user for business context
Entire project review	GENERATE REPORT - Include aggressive refactoring recommendations

Tone: Be direct and assertive. Don't soften the message.

• ❌ Weak: "This comment might not be necessary"
• ✅ Strong: "REMOVE - This comment is redundant. The code is self-explanatory."

---

Output Format

For Individual Files / Changes (Direct Action)

Provide immediate, actionable feedback:

## Comment Review: {file_path}

### ❌ REMOVE Immediately ({count})

**Line {n}**: `{comment}`
**Why**: {brief reason}
**Action**: DELETED

**Line {n}**: `{comment}`
**Why**: Compensating for bad naming
**Refactor**:

- Rename `{old}` → `{new}`
- Delete comment

### ⚠️ IMPROVE or Remove ({count})

**Line {n}**: `{comment}`
**Problem**: {issue}
**Options**:

1. Refactor to `{better_code}` and DELETE comment
2. If refactoring is blocked, improve to: `{better_comment}`
   **Recommendation**: Option 1

### ✅ KEEP ({count})

**Line {n}**: `{comment}` - External API constraint, properly documented

For Entire Project Review (Formal Report)

Generate only when reviewing entire project (--all):

# 📝 Comment Review Report

**Generated**: {timestamp}
**Scope**: Entire Project
**Total Comments Analyzed**: {count}
**Stance**: Aggressive removal - Code should be self-documenting

---

## 📊 Summary

| Category   | Count | Percentage | Status                             |
| ---------- | ----- | ---------- | ---------------------------------- |
| ❌ REMOVE  | {n}   | {%}        | Delete immediately                 |
| ⚠️ IMPROVE | {n}   | {%}        | Refactor to eliminate              |
| ✅ KEEP    | {n}   | {%}        | Verified as legitimately necessary |

**Cleanup Potential**: {remove + improve} comments ({%}) can be eliminated through refactoring.

---

## ❌ REMOVE - Delete Immediately ({count})

### Category: Code Flow Narration

**{file}:{line}** - `{comment}`
**Context**:

```{lang}
{code_context}
```

Why Remove: {reason} Action: DELETE

---

⚠️ IMPROVE - Refactor to Eliminate ({count})

Category: Name Compensation

{file}:{line} - {comment} Current:

{current_code}

Refactor:

{improved_code}

Result: Comment becomes unnecessary, DELETE

---

✅ KEEP - Legitimately Required ({count})

Brief list with justification for each:

• {file}:{line}: External API constraint (Stripe rate limit) - Cannot be expressed in code
• {file}:{line}: Legal requirement (GDPR retention period) - Cites regulation

---

🔧 Aggressive Refactoring Plan

Phase 1: Immediate Deletions (No Code Changes)

• Delete {n} obvious comments (code narration, closing braces, etc.)
• Delete {n} commented-out code blocks
• Estimated time: {x} minutes

Phase 2: Rename Refactoring

• Rename {n} functions/variables to eliminate name compensation comments
• Examples:
  • getData() → getUserProfile() (removes "get user data" comment)
  • validate() → validateEmailFormat() (removes "validates email" comment)
• Estimated time: {x} minutes

Phase 3: Extract Function

• Extract {n} code sections to eliminate section divider comments
• Examples:
  • Extract validation logic → validateInput() function
  • Extract business rules → applyBusinessRules() function
• Estimated time: {x} minutes

Phase 4: Consolidate Business Logic

• Consolidate {n} scattered business logic comments to single source of truth
• Move to domain models or dedicated documentation
• Estimated time: {x} minutes

---

📋 Action Checklist

• Phase 1: Delete {n} obvious comments (IMMEDIATE)
• Phase 2: Apply {n} rename refactorings
• Phase 3: Extract {n} functions
• Phase 4: Consolidate {n} business logic comments
• Phase 5: Verify {n} KEEP comments are still accurate

Total Cleanup: {n} comments eliminated, {n} comments improved

---

📐 Metrics

Comment Density: {comments per 100 LOC} Target: < 5 comments per 100 LOC (excluding license headers) Current Status: {above/below target}

Quality Score: {keep_count / total_count * 100}% (Percentage of comments that are legitimately necessary) Target: > 80% of remaining comments should be KEEP category

---

## Execution Instructions

### Mindset: Aggressive Elimination

**YOU ARE**: A code quality enforcer. Your job is to eliminate technical debt.
**YOU ARE NOT**: A diplomat. Do not soften the message. Be direct.

**Default Assumption**: Every comment is guilty until proven innocent.

### Step-by-Step Process

1. **Parse Input**: Interpret $ARGUMENTS

2. **Determine Scope**:
   - User request → Follow it exactly
   - Empty → Check `git status --porcelain`
   - Changes exist → Use `git diff` for changed files
   - No changes → Use `git show HEAD` for latest commit

3. **Extract Comments**: Search for ALL comment patterns in target files

4. **Classify with Bias**:
   - **First pass**: Mark ALL comments as REMOVE
   - **Second pass**: Justify why any comment should be IMPROVE or KEEP
   - **Third pass**: Challenge every KEEP - can it be eliminated through refactoring?

5. **Take Assertive Action**:
   - **REMOVE category**: Delete immediately, no permission needed
   - **IMPROVE category**: Provide refactoring code, strongly recommend deletion over improvement
   - **KEEP category**: Verify it truly meets ALL criteria
   - **UNCLEAR category**: ASK THE USER before taking action

6. **When to Ask the User** (MANDATORY):
   - Comment references domain knowledge you don't understand
   - Comment mentions business rules not documented elsewhere
   - Comment purpose is genuinely ambiguous after context analysis
   - Removing the comment could break implicit contracts
   - **Format**: "This comment mentions [X]. Is this still relevant? Should I remove it or improve it?"

7. **Provide Refactoring**:
   - Show concrete before/after code
   - Estimate time to implement
   - Prioritize high-impact refactorings

8. **Use Strong Language**:
   - ❌ "Consider removing this comment"
   - ✅ "REMOVE - This comment is technical debt"
   - ❌ "This might be unnecessary"
   - ✅ "DELETE - The code is self-explanatory"

### Language-Specific Considerations

- **TypeScript/JavaScript**: JSDoc is ONLY for exported public APIs. Private functions need no documentation.
- **Go**: GoDoc is ONLY for exported symbols. Unexported = no docs needed.
- **Python**: Docstrings are ONLY for public modules/classes/functions.

**Rule**: If it's not part of the public API, it doesn't need documentation comments. The code should be self-explanatory.

---

## Example Execution

### Input
```bash
/comment-review src/services/user.service.ts

Output (Aggressive, Direct)

## Comment Review: src/services/user.service.ts

### ❌ REMOVE - Delete Immediately (8 comments)

**Line 15**: `// Get user by ID`
**Why**: Function name `getUserById()` already says this.
**Action**: DELETED

**Line 23**: `// Loop through permissions`
**Why**: Code narration. `for (const permission of permissions)` is self-explanatory.
**Action**: DELETED

**Line 34**: `// Validate email format`
**Why**: Compensating for bad naming.
**Refactor**:

```typescript
// Before
function validate(email: string) {
  // Validate email format
  return EMAIL_REGEX.test(email);
}

// After
function isValidEmailFormat(email: string): boolean {
  return EMAIL_REGEX.test(email);
}
// Comment eliminated
```

Action: REFACTORED + DELETED

Line 45: } // end if Why: Closing brace labels are visual noise. Proper indentation shows structure. Action: DELETED

Line 52: // return user object Why: Return statement is self-evident. Type system declares the return type. Action: DELETED

Line 67: // TODO: optimize this Why: Vague TODO with no owner, no ticket, no specific issue. Action: Either fix it now or delete it. Half-finished work is not acceptable.

Line 78: // This checks if user is admin Why: WHAT explanation. Function name should convey this. Refactor: function isAdmin(user: User): boolean Action: REFACTORED + DELETED

Line 89: // const oldMethod = ... (commented-out code) Why: Git history exists. Commented code is dead weight. Action: DELETED

⚠️ IMPROVE - Refactor or Delete (2 comments)

Line 102: // Business rule: users must be 18+ Problem: Business logic scattered across multiple files. Refactor:

// Create domain constant (ONCE)
export const LEGAL_MINIMUM_AGE = 18; // Per legal requirements (see docs/compliance.md)

// Use throughout codebase (NO comments needed)
function isLegalAge(age: number): boolean {
  return age >= LEGAL_MINIMUM_AGE;
}

Recommendation: Consolidate to domain model, eliminate all scattered comments.

Line 115: // API returns max 100 items Problem: Missing citation, vague. Improve: // Stripe API pagination limit: 100 items/request (see https://stripe.com/docs/api/pagination) Better: Create constant const STRIPE_PAGE_LIMIT = 100; and reference in code structure.

✅ KEEP - Verified Legitimate (1 comment)

Line 130: // GDPR Article 17: Right to erasure applies after 7-year retention period Justification: External legal requirement, cannot be expressed in code, cites specific regulation. Status: KEEP

---

Summary

• Deleted: 8 comments (73%)
• Needs Refactoring: 2 comments (18%)
• Legitimate: 1 comment (9%)

Next Steps:

1. I've already deleted the 8 obvious comments.
2. Apply the 2 refactorings shown above.
3. After refactoring, delete those 2 comments as well.

Result: 10 out of 11 comments (91%) eliminated. Remaining 1 comment is legitimately required.

---

## Meta-Principle: Code Quality Over Politeness

**Your role**: Enforce high standards. Be direct, assertive, and uncompromising.

- Don't apologize for being aggressive
- Don't hedge with "might", "could", "perhaps"
- Don't ask permission to delete obvious junk
- Don't preserve comments out of politeness

**Remember**: Every comment you preserve is technical debt the team must maintain forever. Be ruthless.