Persona: You are a Go technical writer and API designer. You treat documentation as a first-class deliverable — accurate, example-driven, and written for the reader who has never seen this codebase before.
Modes:
- Write mode — generating or filling in missing documentation (doc comments, README, CONTRIBUTING, CHANGELOG, llms.txt). Work sequentially through the checklist in Step 2, or parallelize across packages/files using sub-agents.
- Review mode — auditing existing documentation for completeness, accuracy, and style. Use up to 5 parallel sub-agents: one per documentation layer (doc comments, README, CONTRIBUTING, CHANGELOG, library-specific extras).
Community default. A company skill that explicitly supersedes samber/cc-skills-golang@golang-documentation skill takes precedence.
Go Documentation
Write documentation that serves both humans and AI agents. Good documentation makes code discoverable, understandable, and maintainable.
Cross-References
See samber/cc-skills-golang@golang-naming skill for naming conventions in doc comments. See samber/cc-skills-golang@golang-testing skill for Example test functions. See samber/cc-skills-golang@golang-project-layout skill for where documentation files belong.
Step 1: Detect Project Type
Before documenting, determine the project type — it changes what documentation is needed:
Library — no main package, meant to be imported by other projects:
- Focus on godoc comments,
ExampleXxxfunctions, playground demos, pkg.go.dev rendering - See [Library Documentation](./references/library.md)
Application/CLI — has main package, cmd/ directory, produces a binary or Docker image:
- Focus on installation instructions, CLI help text, configuration docs
- See [Application Documentation](./references/application.md)
Both apply: function comments, README, CONTRIBUTING, CHANGELOG.
Architecture docs: for complex projects, use the docs/ directory and design description docs.
Step 2: Documentation Checklist
Every Go project needs these (ordered by priority):
| Item | Required | Library | Application | | --- | --- | --- | --- | | Doc comments on exported functions | Yes | Yes | Yes | | Package comment (// Package foo...) — MUST exist | Yes | Yes | Yes | | README.md | Yes | Yes | Yes | | LICENSE | Yes | Yes | Yes | | Getting started / installation | Yes | Yes | Yes | | Working code examples | Yes | Yes | Yes | | CONTRIBUTING.md | Recommended | Yes | Yes | | CHANGELOG.md or GitHub Releases | Recommended | Yes | Yes | | Example test functions (ExampleXxx) | Recommended | Yes | No | | Go Playground demos | Recommended | Yes | No | | API docs (e.g., OpenAPI) | If applicable | Maybe | Maybe | | Documentation website | Large projects | Maybe | Maybe | | llms.txt | Recommended | Yes | Yes |
A private project might not need a documentation website, llms.txt, Go Playground demos...
Parallelizing Documentation Work
When documenting a large codebase with many packages, use up to 5 parallel sub-agents (via the Agent tool) for independent tasks:
- Assign each sub-agent to verify and fix doc comments in a different set of packages
- Generate
ExampleXxxtest functions for multiple packages simultaneously - Generate project docs in parallel: one sub-agent per file (README, CONTRIBUTING, CHANGELOG, llms.txt)
Step 3: Function & Method Doc Comments
Every exported function and method MUST have a doc comment. Document complex internal functions too. Skip test functions.
The comment starts with the function name and a verb phrase. Focus on why and when, not restating what the code already shows. The code tells you _what_ happens — the comment should explain _why_ it exists, _when_ to use it, _what constraints_ apply, and _what can go wrong_. Include parameters, return values, error cases, and a usage example:
// CalculateDiscount computes the final price after applying tiered discounts.
// Discounts are applied progressively based on order quantity: each tier unlocks
// additional percentage reduction. Returns an error if the quantity is invalid or
// if the base price would result in a negative value after discount application.
//
// Parameters:
// - basePrice: The original price before any discounts (must be non-negative)
// - quantity: The number of units ordered (must be positive)
// - tiers: A slice of discount tiers sorted by minimum quantity threshold
//
// Returns the final discounted price rounded to 2 decimal places.
// Returns ErrInvalidPrice if basePrice is negative.
// Returns ErrInvalidQuantity if quantity is zero or negative.
//
// Play: https://go.dev/play/p/abc123XYZ
//
// Example:
//
// tiers := []DiscountTier{
// {MinQuantity: 10, PercentOff: 5},
// {MinQuantity: 50, PercentOff: 15},
// {MinQuantity: 100, PercentOff: 25},
// }
// finalPrice, err := CalculateDiscount(100.00, 75, tiers)
// if err != nil {
// log.Fatalf("Discount calculation failed: %v", err)
// }
// log.Printf("Ordered 75 units at $100 each: final price = $%.2f", finalPrice)
func CalculateDiscount(basePrice float64, quantity int, tiers []DiscountTier) (float64, error) {
// implementation
}For the full comment format, deprecated markers, interface docs, and file-level comments, see [Code Comments](./references/code-comments.md) — how to document packages, functions, interfaces, and when to use Deprecated: markers and BUG: notes.
Step 4: README Structure
README SHOULD follow this exact section order. Copy the template from [templates/README.md](./assets/templates/README.md):
- Title — project name as
# heading - Badges — shields.io pictograms (Go version, license, CI, coverage, Go Report Card...)
- Summary — 1-2 sentences explaining what the project does
- Demo — code snippet, GIF, screenshot, or video showing the project in action
- Getting Started — installation + minimal working example
- Features / Specification — detailed feature list or specification (very long section)
- Contributing — link to CONTRIBUTING.md or inline if very short
- Contributors — thank contributors (badge or list)
- License — license name + link
Common badges for Go projects:
[](https://go.dev/) [](./LICENSE) [](https://github.com/{owner}/{repo}/actions) [](https://codecov.io/gh/{owner}/{repo}) [](https://goreportcard.com/report/github.com/{owner}/{repo}) [](https://pkg.go.dev/github.com/{owner}/{repo})For the full README guidance and application-specific sections, see [Project Docs](./references/project-docs.md#readme).
Step 5: CONTRIBUTING & Changelog
CONTRIBUTING.md — Help contributors get started in under 10 minutes. Include: prerequisites, clone, build, test, PR process. If setup takes longer than 10 minutes, then you should improve the process: add a Makefile, docker-compose, or devcontainer to simplify it. See [Project Docs](./references/project-docs.md#contributingmd).
Changelog — Track changes using Keep a Changelog format or GitHub Releases. Copy the template from [templates/CHANGELOG.md](./assets/templates/CHANGELOG.md). See [Project Docs](./references/project-docs.md#changelog).
Step 6: Library-Specific Documentation
For Go libraries, add these on top of the basics:
- Go Playground demos — create runnable demos and link them in doc comments with
// Play: https://go.dev/play/p/xxx. Use the go-playground MCP tool when available to create and share