Context
Google and collaborators announced Agentic Resource Discovery (ARD), an open proposal for publishing, indexing and verifying agentic tools and capabilities across organizational boundaries.
What changed
The June 17 announcement introduced domain-hosted capability catalogs and federated registries that can discover MCP servers, A2A agents, skills and other callable services; it also described trust metadata and direct native-protocol connections.
Why it matters
Agentic discovery gains a distinct search and verification layer for callable services, separate from conventional web-page indexing and generative-answer citations.
Visibility OS interpretation
Visibility OS treats ARD as an agent-capability discovery proposal, not as evidence of improved organic Google Search rankings, AI Overviews visibility or ChatGPT/Gemini citations. The launch article's ai-catalog.json example is superseded by the later v0.91 specification.
What remains uncertain
How broadly will agents and registries adopt ARD? Which consumer agents will discover ARD manifests in production? What are the real discovery and invocation rates?
Evidence claims
On June 17, 2026, Google publicly announced Agentic Resource Discovery (ARD) as an open specification using publisher-controlled catalogs and federated registries for discovery and verification of agentic capabilities.
Related historical records
ARD v0.91 defines JSON-LD agent discovery and the ard.json manifest path
That record expands this event.