Capability Cards: Proving What an Agent Can Do, Not Just What It Says
Descriptor formats like A2A's AgentCard tell you what an agent claims it can do. None of them tell you whether the claim is bound to a key you trust, or whether the agent's actual behavior matches. Here is the arc we shipped to close that gap: a predicate registry, signed capability cards, per-actor signing that makes an agent's identity provable, revocation, and the same verdict in the browser as on the command line.