Markdown Linter Fixer

Markdown Linter Fixer

Contents

• [Overview](#overview)
• [When to Use This Skill](#when-to-use-this-skill)
• [Workflow Process](#workflow-process)
• [Phase 1: Environment Setup & Prerequisites](#phase-1-environment-setup--prerequisites)
• [Phase 2: Diagnostic Assessment](#phase-2-diagnostic-assessment)
• [Phase 3: Issue Analysis](#phase-3-issue-analysis)
• [Phase 4: Automatic Fixes](#phase-4-automatic-fixes)
• [Phase 5: Manual Fixes](#phase-5-manual-fixes)
• [Phase 6: Verification & Reporting](#phase-6-verification--reporting)
• [Quick Reference Checklist](#quick-reference-checklist)
• [Key Principles](#key-principles)
• [Common Scenarios](#common-scenarios)
• [Resources](#resources)

Overview

Systematically fix linting issues in *.md files using markdownlint-cli2 through a structured workflow that diagnoses, fixes automatically where possible, and guides manual fixes when needed.

When to Use This Skill

Use this skill when:

• Fixing markdown linting errors in projects
• Standardizing markdown formatting across multiple files
• Addressing ordered list numbering issues (MD029)
• Preparing markdown documentation for quality standards
• Setting up markdown linting for the first time in a project

Workflow Process

Phase 1: Environment Setup & Prerequisites

Verify markdownlint-cli2 Installation

Check if markdownlint-cli2 is installed:

markdownlint-cli2 --version

If missing, install it globally via npm:

npm install -g markdownlint-cli2

Handle any permission or installation errors by suggesting:

• Local installation: npm install --save-dev markdownlint-cli2
• Using npx: npx markdownlint-cli2
• User-specific npm directory configuration

Configuration File Check

Look for existing markdown configuration files in the project root:

• .markdownlint-cli2.jsonc
• .markdownlint.json
• .markdownlint.yaml
• .markdownlint.yml
• .markdownlintrc

If none exist, create .markdownlint-cli2.jsonc with:

{
  "config": {
    "MD013": false
  },
  "ignores": []
}

This disables max line length warnings while keeping other rules active. The ignores array can be used to exclude specific files from linting (e.g., example files with intentional errors).

IMPORTANT - Configuration Policy:

• Do not ignore/hide linting errors by modifying .markdownlint-cli2.jsonc
• Only modify the ignores array based on:
• Explicit user input or approval
• Content from .gitignore file (files already ignored by git)
• Always ask the user before adding files to the ignore list
• Never suppress errors without user consent - fix them instead

Phase 2: Diagnostic Assessment

Initial Root-Level Scan

Run linter on root-level markdown files:

markdownlint-cli2 "*.md"

Document all issues found, including:

• Error codes (e.g., MD029, MD001, MD032)
• File names and line numbers
• Brief description of each issue

Comprehensive Recursive Scan

Scan all markdown files including subdirectories:

markdownlint-cli2 "**/*.md"

This includes files in directories like:

• docs/
• guides/
• Any other subdirectories containing markdown

Create a complete inventory of all issues across the project.

Phase 3: Issue Analysis

Categorize Errors by Type

Group all identified linting errors by error code:

• Track frequency of each error type
• Identify which errors are auto-fixable
• Flag special attention areas (especially MD029, which often requires understanding indentation issues)

Common error types:

• MD001: Heading levels should increment by one level at a time
• MD009: Trailing spaces
• MD010: Hard tabs
• MD012: Multiple consecutive blank lines
• MD029: Ordered list item prefix (requires special attention - often caused by improper indentation)
• MD032: Lists should be surrounded by blank lines
• MD047: Files should end with a single newline character

Document patterns such as:

• "Found 15 MD029 errors across 5 files"
• "MD032 appears in all documentation files"
• "MD029 errors primarily in files with code blocks within lists"

Phase 4: Automatic Fixes

Execute Auto-Fix

Run the auto-fix command to correct all auto-fixable issues:

markdownlint-cli2 "**/*.md" --fix

This command will:

• Automatically fix formatting issues where possible
• Preserve original content intent
• Modify files in place

Monitor for Issues

Watch for:

• Errors during the fix process
• Files that couldn't be modified (permissions)
• Any unexpected side effects

Document what was fixed automatically versus what remains.

Phase 5: Manual Fixes

Handle MD029 Issues

For remaining MD029 (ordered list item prefix) issues:

Load and consult references/MD029-Fix-Guide.md for detailed guidance on:

• Understanding the root cause: improper indentation of content between list items
• Proper 4-space indentation for code blocks within lists
• Indentation requirements for paragraphs, blockquotes, and nested content
• Common mistakes and how to avoid them
• Real-world examples showing before/after fixes
• Alternative solutions and when to use them

Key insight: MD029 errors often occur when code blocks, paragraphs, or other content between list items lack proper indentation (typically 4 spaces), causing markdown parsers to break list continuity.

Apply Manual Corrections

For issues not auto-fixed:

• Open affected files
• Apply fixes according to error type
• Maintain consistency with existing markdown style
• Verify fixes don't break content

Phase 6: Verification & Reporting

Re-run Linter

Confirm all issues are resolved:

markdownlint-cli2 "**/*.md"

If no errors appear, linting is complete. If errors remain, document them for additional manual fixes.

Generate Summary Report

Provide a comprehensive summary including:

1. Files Processed

• Total count
• List of files modified
• Any files skipped or with errors

1. Issues Fixed by Type

• Count of each error type fixed
• Auto-fixed vs. manually fixed
• Special notes on MD029 fixes

1. Remaining Issues (if any)

• Error codes still present
• Files requiring manual attention
• Recommended next steps

1. Completion Status

• Confirmation of successful completion, or
• Clear explanation of remaining work needed
• Any error details with suggested solutions

Quick Reference Checklist

• [ ] Verify markdownlint availability: markdownlint-cli2 --version
• [ ] Create or validate markdownlint config (.markdownlint-cli2.jsonc preferred)
• [ ] Run diagnostics: markdownlint-cli2 "**/*.md"
• [ ] Apply auto-fixes: markdownlint-cli2 "**/*.md" --fix
• [ ] Resolve remaining issues manually using references/MD029-Fix-Guide.md and references/MD036-Guide.md as needed
• [ ] Re-run verification: markdownlint-cli2 "**/*.md"
• [ ] Summarize files changed, issue types fixed, and any remaining blockers

Key Principles

• Preserve content intent: fix formatting without changing meaning.
• Respect project configuration: do not override existing lint rules unless explicitly requested.
• Do not suppress or hide errors without user consent; fix issues rather than masking them.
• Apply progressive fixing: auto-fix first, then manual fixes for remaining issues.
• Report clearly: what was found, what was fixed, and what still needs action.

Common Scenarios

| User Request Pattern | Workflow Emphasis | References | | --- | --- | --- | | "Set up markdown linting for my documentation" | Phase 1 -> Phase 2 -> Phase 4 -> Phase 6 | N/A | | "Fix all markdown linting errors in my project" | Phase 2 -> Phase 3 -> Phase 4 -> Phase 5 -> Phase 6 | Load MD029/MD036 guides only if related errors remain | | "Fix MD029" / "ordered list issues" | Phase 2 (target MD029) -> Phase 4 -> Phase 5 -> Phase 6 | references/MD029-Fix-Guide.md |

Resources

references/

MD029-Fix-Guide.md

Comprehensive guide for handling MD029 (ordered list item prefix) errors, focusing on the root cause: improper indentation. This reference provides:

• Explanation of why MD029 errors occur (content breaking list continuity)
• Proper indentation rules: 4 spaces for code blocks, paragraphs, and other content
• Indentation table showing requirements for different content types
• Common mistakes with clear ❌ wrong vs ✅ correct examples
• Real-world before/after examples
• Alternative solutions and when to use markdownlint-disable comments
• Best practices for maintaining list continuity
• Verification steps

Load this file when MD029 errors persist after auto-fix, or when user needs guidance on fixing ordered list issues. The guide is particularly valuable when lists contain code blocks or mixed content.

MD036-Guide.md

Comprehensive style guide for avoiding MD036 (no emphasis as heading) errors. This reference provides:

• Clear explanation of the MD036 rule and why it matters
• Wrong vs. correct examples showing bold text vs. proper heading syntax
• Heading level hierarchy guidelines (h1 through h6)
• Common violations to avoid when creating markdown files
• Best practices for using headings vs. bold text
• Quick checklist for markdown file creation and modification

Load this file when creating new markdown documentation or when encountering MD036 errors. Use as a reference to maintain consistent heading structure and avoid using bold text as heading substitutes.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: s2005
• Source: s2005/markdown-linter-fixer-skill
• License: MIT

Install and usage instructions live in the source repository linked above.