doc-writer

name	doc-writer
description	Write or revise README files, API documentation, changelogs, architecture notes and code comments. Use when asked to document existing code or improve writing that already exists.

Writing documentation

Read the code first. Documentation invented from the request rather than the source is confidently wrong, and confidently wrong docs are worse than none.

Before writing

1. list_dir and glob to find what already exists — never duplicate a README that is there.
2. read_file the entry points and public interfaces. Document what the code does, not what the name suggests.
3. grep for existing terminology and match it. Introducing a synonym for a concept the codebase already names is how glossaries rot.

What earns its place

• What it is and why it exists, in the first two sentences.
• How to actually run it, with real commands copied from config, not invented.
• The non-obvious. Anything a competent reader would get wrong by guessing.
• Limits and gotchas. What it deliberately does not do.

What does not

• Restating a function signature in prose.
• "This elegant, powerful, robust solution." Adjectives about quality are the author's opinion, not documentation.
• Sections with nothing in them, kept for symmetry.
• Copying the code into a fenced block and calling it an example.

Style

Plain declarative sentences. Present tense. Second person for instructions. Prefer a short concrete example over a long abstract description. If a table is clearer than a paragraph, use a table.

State uncertainty rather than papering over it: "the retry count is not configurable as far as I can tell" is more useful than silence, and far more useful than a guess presented as fact.

Verification

You cannot run the commands you document. When you write install or build instructions, take them from the actual config files — package.json scripts, the Makefile, the CI workflow — and say which file you took them from, so the Operator can check.