documentation

Documentation Skill

Goal

Create comprehensive, practical documentation for newly implemented features. Help users understand what the feature does and help developers maintain and extend it.

Activation Triggers

• User asks to "document", "write docs", or "add documentation"
• After completing feature implementation
• User asks to update README or GEMINI.md

Core Principle

The code is the source of truth. Use PRD and plan for context only—document what was actually built, not what was planned.

Process

1. Understand the Implementation

# Find changed files
git diff --name-only HEAD~10 2>/dev/null

# Get summary of changes
git log --oneline -10 2>/dev/null

# Find the feature's main files
find src -name "*.ts" -newer [plan_file] 2>/dev/null | head -20

2. Identify Documentation Needs

Questions:

• What does a user need to know to use this feature?
• What does a developer need to know to maintain/extend it?
• What patterns or conventions were established?
• Where does this fit in existing documentation?

3. Determine Documentation Locations

Based on feature scope:

Code Comments (Always Required)

Add inline documentation for:

• Complex algorithms or business logic
• Non-obvious implementation decisions
• Public APIs, functions, or classes
• Important type definitions

README Files (For Significant Changes)

Update if the feature:

• Changes how to run or deploy
• Adds new dependencies
• Changes architecture significantly
• Adds major user-facing capabilities

Developer Guides (For New Patterns)

Create if the feature:

• Introduces new patterns to reuse
• Implements a new system component
• Requires specific knowledge to maintain
• Establishes conventions for others

GEMINI.md (For AI Context)

Update if the feature:

• Introduces new commands
• Adds new directories
• Establishes new patterns
• Changes tech stack

Documentation Standards

Code Comments

Use JSDoc format for TypeScript/JavaScript: