A2A Agent Discovery — Capability Matching & Agent Registry

I will build an A2A agent discovery system — a registry where agents publish their capabilities via agent cards, a capability matching service that enables requesting agents to find the best available agent for a task, and an agent health monitoring system tracking availability across the registered agent population. A2A capability discovery without a matching service requires every calling agent to know which specific agent to call — defeating the purpose of the protocol's capability abstraction; a matching service that evaluates agent card capabilities against task requirements enables true capability-based routing that survives agent additions and changes without calling-agent modification.

The system covers an agent card registry with publication and update API, a semantic capability matching service using embedding-based similarity, availability and health monitoring for registered agents, a registry API for agent lookup, and a management interface for registry administration.