Structured data for agents

JSON-LD with schema.org types gives agents typed facts about your page. It is the same markup search engines use, and agents lean on it just as heavily.

What it is

Structured data is a machine-readable description of what a page is about, embedded in the page itself. The dominant vocabulary is schema.org, and the recommended syntax is JSON-LD: a <script type="application/ld+json"> block inside <head>.

The same markup that drives rich results in Google also helps agents understand who wrote a page, what it describes, and how it relates to other entities. Agents do not parse open prose well; they parse JSON-LD reliably.

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "Setting up CSP",
  "datePublished": "2026-05-12",
  "author": {
    "@type": "Person",
    "name": "Joost de Valk",
    "url": "https://example.com/about/joost"
  },
  "publisher": {
    "@type": "Organization",
    "name": "Example Corp",
    "url": "https://example.com"
  }
}
</script>

Why it matters

Disambiguation. "Joost de Valk" is text. Person with a url is a typed identity.
Extraction quality. Agents pull facts from JSON-LD with near-perfect accuracy. The same facts in prose are guessed.
Cross-page consistency. A consistent Organization block across the site lets agents merge data into a single entity.
Search overlap. What helps agents here is the same work that drives rich results and Knowledge Graph entries.

It is also one of the easiest items in this spec to verify: the markup is right there in the HTML.

How to implement

Pick the types that match your pages. Common ones:

Article, BlogPosting, NewsArticle for editorial content.
Product with Offer, AggregateRating, Review for commerce.
FAQPage and Question for Q&A content.
Person, Organization for entity pages, used as nested references everywhere else.
Event, Recipe, HowTo, JobPosting, LocalBusiness for vertical-specific pages.
BreadcrumbList for breadcrumb trails.
WebSite with SearchAction on the homepage.

Rules to follow:

Use JSON-LD over Microdata or RDFa. Easier to write, easier to keep in sync.
One block per type is fine; multiple blocks per page are also fine.
Reuse @id URIs so agents can link entities across pages.
Mirror what is visible on the page. Schema for content that does not appear violates Google's guidelines and trains agents to mistrust your markup.
Test with the Schema Markup Validator and Google's Rich Results Test.

Common mistakes

Marking up an Article that is actually a category page.
Inflating AggregateRating with fake reviews. Both search engines and agents penalise this when caught.
Leaving stale datePublished or author after a CMS migration.
Forgetting to update structured data when the visible content changes.
Using @type: "WebPage" for everything. Pick a specific type.

Verification

Run the page through validator.schema.org and Google's Rich Results Test.
Fetch the HTML and confirm the JSON-LD is present before JavaScript executes.
Spot-check that the JSON-LD matches what a reader actually sees.