Are we going to need identity checks for AI agents?

I’ve been thinking about agent identity more than agent intelligence lately. With MCP, tool use, agent to agent workflows, and autonomous assistants getting more common, the question is not just “can the agent do the task?” It is also, Is this the same agent that was approved yesterday? or Does it still have the same tools? or Did its permissions change? or Can it prove which action came from which user intent? or Can we replay what happened if two agents hand work off to each other? This feels similar to service accounts, but messier. A service account usually has a known app, known permissions, and known behavior. An AI agent can change behavior based on context, memory, tool descriptions, prompt state, and external inputs. So I’m wondering if agent identity becomes a real layer: signed tool manifests, scoped permissions, action logs, maybe even something like “agent certificates” tied to what the agent is allowed to do. For people building agent systems, are you treating agents like normal app users/service accounts, or are you designing a separate identity and permission model for them?