The way AI agents find tools is broken. Right now, developers hardcode server URLs into config files or dump every available tool description into a context window and pray the model picks the right one. That doesn’t scale when you’re dealing with thousands of potential capabilities, and thin descriptions often lead to bad matches.
A group of engineers from Microsoft, Google, GoDaddy, and Hugging Face have a better idea. They’ve drafted the Agentic Resource Discovery (ARD) specification — an open standard that acts as a discovery layer for agents. It’s not a product or a marketplace. It defines how capabilities get cataloged, indexed, and searched across federated registries. The big shift is moving from a static, install-first model to intent-based search at runtime. An agent describes what it needs in natural language, and ARD returns a ranked list of matching MCP tools, A2A agents, or other services it can invoke on the fly.
Hugging Face has already shipped a reference implementation called the Discover Tool. It taps into the Hub’s existing semantic search over Spaces and wraps the results in ARD-compliant catalog entries. The adapter is smart enough to convert a Space into different formats depending on what the client asks for: a skill (with auto-generated SKILL.md frontmatter), an MCP server entry for Spaces tagged mcp-server, or raw Space metadata. The search endpoint only returns Spaces with a RUNNING stage, which avoids pointing agents at dead resources. You can access it through the hf discover search CLI, a REST API, or an MCP tool.
The spec itself is a two-part deal. Publishers drop a static ai-catalog.json manifest at a well-known URL so agents can find their capabilities. A dynamic POST /search REST API provides live, ranked discovery across those catalogs. The whole thing is an open draft with broad industry participation, and you can start building on it today. For a model that’s always been bottlenecked by what it knows about in advance, the ability to search for capabilities at runtime is a genuine unlock.
