MarkdownLint

Format and lint a markdown document for consistent code formatting, proper list structure, heading hierarchy, and link hygiene. Reads a file, applies all rules, writes the corrected version after confirmation.

Instructions

Step 1: Read the target file

If an argument was provided, use it as the file path. Otherwise, ask which file to lint.

Check TLP before reading:

• GREEN/CLEAR: Read directly
• AMBER: Use safe-read via Bash
• RED: Refuse

Step 2: Schema validation

If mdschema is installed, look for a .mdschema in the file's parent directory (for skills: skills/.mdschema, for agents: agents/.mdschema). If found, run:

mdschema check "<file>" --schema "<schema>"

Report any violations (missing frontmatter fields, heading level skips, depth exceeded). These are structural issues that formatting rules cannot auto-fix — present them to the user as findings.

If mdschema is not installed or no schema exists, skip this step silently.

Step 3: Identify protected zones

Before applying any rules, identify zones that MUST NOT be modified:

Process only unprotected text spans.

Step 4: Apply formatting rules

3a: Backtick filenames

Any word ending in a code-associated extension:

.md, .yaml, .yml, .json, .rs, .sh, .ts, .js, .toml, .base, .css, .html, .py, .go, .lua, .sql, .env, .tlp, .gitignore, .claudeignore

Examples: CLAUDE.md becomes CLAUDE.md, config.yaml becomes config.yaml.

Skip if already backticked, inside a wikilink, or part of a URL path.

3b: Backtick CLI commands and tool names

Recognized patterns:

• Known tools: safe-read, safe-write, blind-metadata, obsidian-base, build-templates, surface, insight, reflect, ekctl, cargo, make, git, npm, shellcheck, jq
• Command invocations with flags: words followed by --flag or -f
• Make targets: make install, make test, make clean
• Compound commands: cargo build, cargo test, git commit

Backtick the full command phrase, not individual words.

3c: Backtick technical identifiers

Exceptions: Tags used as actual functional Obsidian tags — leave as-is. Env vars inside code blocks — skip.

3d: Convert bare URLs

Bare URLs (<https://...> or plain https://... in text):

1. GitHub repo URL: use repo name — [forge-tlp](https://github.com/user/forge-tlp)
2. Well-known service: use service name — [Obsidian](https://obsidian.md/)
3. Other: infer title from URL path or use domain name
4. If WebFetch available and URL is public, fetch the page title

Never convert URLs already inside markdown links [text](url) or code blocks.

3e: Fix list formatting

• Use - for unordered lists (Obsidian convention)
• Proper indentation for child items
• Blank line before and after list blocks (unless inside a callout)

3f: Check heading hierarchy

• No skipped levels (e.g., ## followed by ####)
• Single # H1 at document start (after frontmatter)
• Flag but do not auto-fix if structure is ambiguous

Step 5: Special syntax recognition

Do NOT lint these as errors:

• #tlp/red, #tlp/amber, #tlp/green, #tlp/clear — valid TLP structural markers
• %% @todo ... %%, %% @fixme ... %% — valid Obsidian annotation markers
• ![[embed]] — valid Obsidian embed syntax
• > [!callout] — valid Obsidian callout syntax
• Dataview blocks (dataview, dataviewjs)

Step 6: Confirm changes

Present a summary:

• Count of backticked items by category (filenames, commands, tags, env vars)
• Count of URLs converted
• List/heading fixes
• 2-3 representative before/after examples

Ask the user to confirm before writing.

Step 7: Write the corrected file

• AMBER: use safe-write write via Bash
• GREEN/CLEAR: use Write tool directly
• Preserve all protected zones exactly

Constraints

• Never modify YAML frontmatter content
• Never modify content inside fenced code blocks or inline code
• Never backtick text inside wikilinks
• Never convert wikilinks to markdown links or vice versa
• Never change semantic meaning — only formatting
• Never add backticks to regular English words (e.g., "base" as a noun, "draft" as a verb)
• Preserve all Obsidian-specific syntax
• After linting, suggest the WikiLink skill if the document could benefit from knowledge graph links