Agent Skills: Code Documentation Generator

Code Documentation Generator

Automatically generates comprehensive documentation by analyzing code structure, comments, and patterns. Creates README files, API docs, and inline documentation.

🎯 Use Case Demo

Scenario: New Service Needs Documentation

Before (Manual Process):

Developer Mike creates a new BookingService class with 15 methods. Now he needs to document it:

• Writes README manually - 45 minutes
• Adds XML comments to each method - 30 minutes
• Creates usage examples - 20 minutes
• Forgets to update docs when code changes
• Total: 1.5+ hours

After (With This Skill):

Mike: "Generate documentation for BookingService.cs"

Agent Response:

# BookingService Documentation

## Overview
The `BookingService` manages flight booking operations including
creation, modification, cancellation, and payment processing.

## Dependencies
- `IFlightService` - Flight availability checking
- `IPaymentGateway` - Payment processing
- `IEmailService` - Confirmation emails
- `IBookingRepository` - Data persistence

## Methods

### CreateBookingAsync
Creates a new flight booking for a passenger.

**Parameters:**
| Name | Type | Description |
|------|------|-------------|
| flightId | int | The ID of the flight to book |
| passenger | PassengerInfo | Passenger details |
| paymentInfo | PaymentDetails | Payment information |

**Returns:** `Task<BookingResult>` - Booking confirmation with reference number

**Throws:**
- `FlightFullException` - When no seats available
- `PaymentFailedException` - When payment is declined

**Example:**
```csharp
var result = await bookingService.CreateBookingAsync(
    flightId: 123,
    passenger: new PassengerInfo("John", "Doe", "john@email.com"),
    paymentInfo: new PaymentDetails(cardNumber, expiry, cvv)
);
Console.WriteLine($"Booking confirmed: {result.ReferenceNumber}");

CancelBookingAsync

Cancels an existing booking and processes refund if applicable. ...

**Files Generated:**
- `docs/BookingService.md` - Full documentation
- Updated XML comments in `BookingService.cs`
- Added to `docs/README.md` index

Time Saved: 1.5 hours → 2 minutes (45x faster)

Agent Instructions

When this skill is activated:

1. Analyze Code Structure:

   • Parse the target file(s) using language-specific analysis
   • Extract classes, methods, properties, and their signatures
   • Identify dependencies and inheritance relationships
   • Find existing comments and documentation

2. Infer Documentation:

   • Use method names and parameters to describe purpose
   • Analyze method body to understand behavior
   • Identify exceptions that can be thrown
   • Find return value types and meanings

3. Generate Documentation:

   • Create comprehensive Markdown documentation
   • Include code examples based on usage patterns
   • Add parameter tables with types and descriptions
   • Document exceptions and edge cases

4. Update Inline Comments:

   • Add or update XML documentation comments (C#)
   • Add or update JSDoc comments (JavaScript/TypeScript)
   • Add or update docstrings (Python)

5. Create Index:

   • Update or create docs/README.md with links
   • Organize by namespace/module
   • Add navigation structure

Example Prompts

• "Generate documentation for the Services folder"
• "Document the FlightController class"
• "Create a README for this project"
• "Add XML comments to BookingService.cs"
• "Update docs for the Models folder"

Supported Languages

| Language | Inline Docs | Markdown | Examples | |----------|-------------|----------|----------| | C# | XML Comments | ✅ | ✅ | | TypeScript | JSDoc | ✅ | ✅ | | JavaScript | JSDoc | ✅ | ✅ | | Python | Docstrings | ✅ | ✅ | | Java | Javadoc | ✅ | ✅ |

Benefits

| Metric | Before | After | Improvement | |--------|--------|-------|-------------| | Documentation time | 1.5 hours | 2 min | 45x faster | | Doc coverage | 30-40% | 95%+ | 2.5x coverage | | Doc accuracy | Outdated | Current | Always in sync | | New dev onboarding | 2-3 days | 1 day | 60% faster |