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• D (30-49): Sparse or outdated
• F (0-29): Missing or severely outdated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)