anthropics/claude-md-improver

CLAUDE.md Improver

Audit, evaluate, and improve CLAUDE.md files across a codebase to ensure Claude Code has optimal project context.

This skill can write to CLAUDE.md files. After presenting a quality report and getting user approval, it updates CLAUDE.md files with targeted improvements.

Workflow

Phase 1: Discovery

Find all CLAUDE.md files in the repository:

find . -name "CLAUDE.md" -o -name ".claude.md" -o -name ".claude.local.md" 2>/dev/null | head -50

File Types & Locations:

| Type | Location | Purpose | |------|----------|---------| | Project root | ./CLAUDE.md | Primary project context (checked into git, shared with team) | | Local overrides | ./.claude.local.md | Personal/local settings (gitignored, not shared) | | Global defaults | ~/.claude/CLAUDE.md | User-wide defaults across all projects | | Package-specific | ./packages/*/CLAUDE.md | Module-level context in monorepos | | Subdirectory | Any nested location | Feature/domain-specific context |

Note: Claude auto-discovers CLAUDE.md files in parent directories, making monorepo setups work automatically.

Phase 2: Quality Assessment

For each CLAUDE.md file, evaluate against quality criteria. See references/quality-criteria.md for detailed rubrics.

Quick Assessment Checklist:

| Criterion | Weight | Check | |-----------|--------|-------| | Commands/workflows documented | High | Are build/test/deploy commands present? | | Architecture clarity | High | Can Claude understand the codebase structure? | | Non-obvious patterns | Medium | Are gotchas and quirks documented? | | Conciseness | Medium | No verbose explanations or obvious info? | | Currency | High | Does it reflect current codebase state? | | Actionability | High | Are instructions executable, not vague? |

Quality Scores:

• A (90-100): Comprehensive, current, actionable
• B (70-89): Good coverage, minor gaps
• C (50-69): Basic info, missing key sections
• D (30-49): Sparse or outdated
• F (0-29): Missing or severely outdated

Phase 3: Quality Report Output

ALWAYS output the quality report BEFORE making any updates.

Format:

## CLAUDE.md Quality Report

### Summary
- Files found: X
- Average score: X/100
- Files needing update: X

### File-by-File Assessment

#### 1. ./CLAUDE.md (Project Root)
**Score: XX/100 (Grade: X)**

| Criterion | Score | Notes |
|-----------|-------|-------|
| Commands/workflows | X/20 | ... |
| Architecture clarity | X/20 | ... |
| Non-obvious patterns | X/15 | ... |
| Conciseness | X/15 | ... |
| Currency | X/15 | ... |
| Actionability | X/15 | ... |

**Issues:**
- [List specific problems]

**Recommended additions:**
- [List what should be added]

#### 2. ./packages/api/CLAUDE.md (Package-specific)
...

Phase 4: Targeted Updates

After outputting the quality report, ask user for confirmation before updating.

Update Guidelines (Critical):

1. Propose targeted additions only - Focus on genuinely useful info:

   • Commands or workflows discovered during analysis
   • Gotchas or non-obvious patterns found in code
   • Package relationships that weren't clear
   • Testing approaches that work
   • Configuration quirks

2. Keep it minimal - Avoid:

   • Restating what's obvious from the code
   • Generic best practices already covered
   • One-off fixes unlikely to recur
   • Verbose explanations when a one-liner suffices

3. Show diffs - For each change, show:

   • Which CLAUDE.md file to update
   • The specific addition (as a diff or quoted block)
   • Brief explanation of why this helps future sessions

Diff Format:

### Update: ./CLAUDE.md

**Why:** Build command was missing, causing confusion about how to run the project.

```diff
+ ## Quick Start
+
+ ```bash
+ npm install
+ npm run dev  # Start development server on port 3000
+ ```

### Phase 5: Apply Updates

After user approval, apply changes using the Edit tool. Preserve existing content structure.

## Templates

See [references/templates.md](references/templates.md) for CLAUDE.md templates by project type.

## Common Issues to Flag

1. **Stale commands**: Build commands that no longer work
2. **Missing dependencies**: Required tools not mentioned
3. **Outdated architecture**: File structure that's changed
4. **Missing environment setup**: Required env vars or config
5. **Broken test commands**: Test scripts that have changed
6. **Undocumented gotchas**: Non-obvious patterns not captured

## User Tips to Share

When presenting recommendations, remind users:

- **`#` key shortcut**: During a Claude session, press `#` to have Claude auto-incorporate learnings into CLAUDE.md
- **Keep it concise**: CLAUDE.md should be human-readable; dense is better than verbose
- **Actionable commands**: All documented commands should be copy-paste ready
- **Use `.claude.local.md`**: For personal preferences not shared with team (add to `.gitignore`)
- **Global defaults**: Put user-wide preferences in `~/.claude/CLAUDE.md`

## What Makes a Great CLAUDE.md

**Key principles:**
- Concise and human-readable
- Actionable commands that can be copy-pasted
- Project-specific patterns, not generic advice
- Non-obvious gotchas and warnings

**Recommended sections** (use only what's relevant):
- Commands (build, test, dev, lint)
- Architecture (directory structure)
- Key Files (entry points, config)
- Code Style (project conventions)
- Environment (required vars, setup)
- Testing (commands, patterns)
- Gotchas (quirks, common mistakes)
- Workflow (when to do what)