# TOOLING-ITD-003: Custom Lint Rules ## CONTEXT Generic markdown linting doesn't understand our document types. An ITD must have specific sections (Context, Problem, Options, Reasoning, Implications). A Data Structure needs an Overview. ## PROBLEM How should we enforce document-type-specific structure? ## OPTIONS CONSIDERED 1. **Manual review only** - Reviewers check structure 2. ✅ **Custom markdownlint rules** - Automated validation per doc type 3. **Schema validation** - YAML frontmatter with JSON schema ## REASONING *Option 1 (Manual):* Reviewers forget. Inconsistent enforcement. *Option 2 (Custom rules):* Markdownlint supports custom rules in JavaScript. We can validate ITD sections, naming conventions, and required content automatically. *Option 3 (Schema):* Adds complexity. Frontmatter is friction. Markdown-native validation is simpler. ## IMPLICATIONS Custom rules implemented: * `itd-required-sections` - ITDs must have all five sections * `itd-valid-sections` - No unexpected sections in ITDs * `itd-single-selected-option` - Exactly one option marked with ✅ * `itd-naming-convention` - Title matches folder prefix * `ds-required-sections` - Data Structures need Overview Rules live in `tooling/lint-rules/` and run via markdownlint config. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://losthex.gitbook.io/losthex-docs/tooling-itds/tooling-itd-003-custom-spec-rules.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.