seo-schema-jsonld (M5)

Structured data is the single highest-leverage signal for both classic rich results and AI citation. Reference: references/schema-tier1.md. Templates: schema/jsonld-templates/.

Audits

Working from the PageSnapshot (rendered_dom if present, else raw_html):

Detect every <script type="application/ld+json"> block; parse JSON; note any inline microdata/RDFa (flag for migration to JSON-LD).
Validate each block: valid JSON, recognized @type, required + recommended properties present per references/schema-tier1.md.
Completeness vs the page's content & vertical: e.g. an article page should have Article/BlogPosting with author (Person), datePublished, dateModified, image, publisher; a product page Product + Offer (price, priceCurrency, availability).
Entity hygiene: stable @id, @graph linkage, sameAs (defer the sameAs audit detail to M6/seo-entity-linking).
Date agreement: schema datePublished/dateModified should match visible dates (cross-check with M13).
Deprecation honesty: if FAQPage/HowTo present, do NOT report them as a rich-result win — label deprecated-for-SERP (still parseable by AI).