lint-clean-markdown

name	lint-clean-markdown
description	Write markdown that passes linting on first attempt by internalizing common rules.
tier	core
applyTo	**/*.md,**/*markdown*,**/*lint*

Lint-Clean Markdown Skill

Write markdown that passes linting on first attempt by internalizing common rules.

Purpose

Eliminate the edit-lint-fix cycle by writing markdown correctly the first time. This skill encodes the most common markdown lint rules as muscle memory.

The Golden Rule

When in doubt: Add a blank line.

90% of markdown lint errors are missing blank lines. Lists, code blocks, and headings all need breathing room.

Core Rules Quick Reference

Rule	Code	Pattern	Mnemonic
Blank lines around lists	MD032	\n- item\n- item\n	"Lists breathe"
Blank lines around fences	MD031	\n```code```\n	"Code breathes"
Blank line before headings	MD022	text\n\n## Head	"Headers breathe"
Use dash for lists	MD004	- not * or +	"Dash dash dash"
No trailing whitespace	MD009	No spaces at line end	"Clean endings"
Single final newline	MD047	One \n at EOF	"One newline"
Language on fences	MD040	```js not ```	"Name your code"
Consistent fence style	MD046	Use ``` not indent	"Fences only"
No bold as heading	MD036	Use ## not **text**	"Headers are headers"
Table separator spacing	MD060	Space around pipes	"Tables breathe too"

Rule Details

MD032: Blank Lines Around Lists

❌ Wrong: Text immediately before/after list

✅ Correct: Blank line before first - AND after last -

**Why**:

- Reason one
- Reason two

**Result**: Something

MD031: Blank Lines Around Code Blocks

❌ Wrong: Text touching the fence markers

✅ Correct: Blank line before opening ``` AND after closing ```

MD022: Blank Lines Before Headings

❌ Wrong: Some text.\n## Heading

✅ Correct: Some text.\n\n## Heading

MD004: Use Dash for Unordered Lists

❌ Wrong: * item or + item

✅ Correct: - item

MD040: Specify Language on Fenced Code

❌ Wrong: ``` (no language)

✅ Correct: ```javascript or ```text or ```markdown

Mermaid-Specific Rules

Template Blocks Use text

When showing a template/pattern (not a renderable diagram), use ```text instead of ```mermaid.

Why: Mermaid parser will fail on placeholder text like [DIAGRAM_TYPE].

Diagram Type Required

Nested Code Block Problem

You cannot nest fenced code blocks in markdown.

When documenting code block rules (like this skill), use:

1. Inline code for short examples: ```js
2. Descriptions instead of showing wrong examples
3. Single examples showing only the correct form

This skill itself demonstrates the solution.

Pre-Write Mental Checklist

Before writing markdown, plan for:

1. ☐ Will I have lists? → Remember blank lines around them
2. ☐ Will I have code blocks? → Remember blank lines around them
3. ☐ Will I show "wrong" examples? → Can't nest fences, describe instead
4. ☐ Will I have tables? → Need | ---- | separator row
5. ☐ Will I have mermaid? → Need diagram type after init