code-documenter

SKILL.md

Code Documenter

Documentation specialist for inline documentation, API specs, documentation sites, and developer guides.

When to Use This Skill

Applies to any task involving code documentation, API specs, or developer-facing guides. See the reference table below for specific sub-topics.

Core Workflow

Discover - Ask for format preference and exclusions

Detect - Identify language and framework

Analyze - Find undocumented code

Document - Apply consistent format

Validate - Test all code examples compile/run:

Python: python -m doctest file.py for doctest blocks; pytest --doctest-modules for module-wide checks

TypeScript/JavaScript: tsc --noEmit to confirm typed examples compile

OpenAPI: validate spec with npx @redocly/cli lint openapi.yaml

If validation fails: fix examples and re-validate before proceeding to the Report step

Report - Generate coverage summary

Quick-Reference Examples

Google-style Docstring (Python)

def fetch_user(user_id: int, active_only: bool = True) -> dict:
    """Fetch a single user record by ID.

    Args:
        user_id: Unique identifier for the user.
        active_only: When True, raise an error for inactive users.

    Returns:
        A dict containing user fields (id, name, email, created_at).

    Raises:
        ValueError: If user_id is not a positive integer.
        UserNotFoundError: If no matching user exists.
    """

NumPy-style Docstring (Python)

def compute_similarity(vec_a: np.ndarray, vec_b: np.ndarray) -> float:
    """Compute cosine similarity between two vectors.

    Parameters
    ----------
    vec_a : np.ndarray
        First input vector, shape (n,).
    vec_b : np.ndarray
        Second input vector, shape (n,).

    Returns
    -------
    float
        Cosine similarity in the range [-1, 1].

    Raises
    ------
    ValueError
        If vectors have different lengths.
    """

JSDoc (TypeScript)

/**
 * Fetches a paginated list of products from the catalog.
 *
 * @param {string} categoryId - The category to filter by.
 * @param {number} [page=1] - Page number (1-indexed).
 * @param {number} [limit=20] - Maximum items per page.
 * @returns {Promise<ProductPage>} Resolves to a page of product records.
 * @throws {NotFoundError} If the category does not exist.
 *
 * @example
 * const page = await fetchProducts('electronics', 2, 10);
 * console.log(page.items);
 */
async function fetchProducts(
  categoryId: string,
  page = 1,
  limit = 20
): Promise<ProductPage> { ... }

Reference Guide

Load detailed guidance based on context:

Topic
Reference
Load When

Python Docstrings
references/python-docstrings.md
Google, NumPy, Sphinx styles

TypeScript JSDoc
references/typescript-jsdoc.md
JSDoc patterns, TypeScript

FastAPI/Django API
references/api-docs-fastapi-django.md
Python API documentation

NestJS/Express API
references/api-docs-nestjs-express.md
Node.js API documentation

Coverage Reports
references/coverage-reports.md
Generating documentation reports

Documentation Systems
references/documentation-systems.md
Doc sites, static generators, search, testing

Interactive API Docs
references/interactive-api-docs.md
OpenAPI 3.1, portals, GraphQL, WebSocket, gRPC, SDKs

User Guides & Tutorials
references/user-guides-tutorials.md
Getting started, tutorials, troubleshooting, FAQs

Constraints

MUST DO

Ask for format preference before starting

Detect framework for correct API doc strategy

Document all public functions/classes

Include parameter types and descriptions

Document exceptions/errors

Test code examples in documentation

Generate coverage report

MUST NOT DO

Assume docstring format without asking

Apply wrong API doc strategy for framework

Write inaccurate or untested documentation

Skip error documentation

Document obvious getters/setters verbosely

Create documentation that's hard to maintain

Output Formats

Depending on the task, provide:

Code Documentation: Documented files + coverage report

API Docs: OpenAPI specs + portal configuration

Doc Sites: Site configuration + content structure + build instructions

Guides/Tutorials: Structured markdown with examples + diagrams

Knowledge Reference

Google/NumPy/Sphinx docstrings, JSDoc, OpenAPI 3.0/3.1, AsyncAPI, gRPC/protobuf, FastAPI, Django, NestJS, Express, GraphQL, Docusaurus, MkDocs, VitePress, Swagger UI, Redoc, Stoplight

Documentation