Why should human accounts, service accounts, service principals, managed identities and AI agent identities be managed separately?

In plain language

In a workplace, an employee badge, an automated-door system credential and a delivery robot's identity should not be the same badge. Each actor must be recognised separately so that the right permissions can be granted and each action can be attributed correctly.

Why this matters

Running automation through a human account obscures accountability, carries excessive authority and may break when that person leaves. Identifying an agent only by a model name also fails to show which particular agent instance performed an action.

Do not confuse

• An identity, an authenticator and a permission are not the same thing.
• An application object and a service principal are not the same object.
• A managed identity is a managed form of identity; its relationship to the resource that uses it must still be tracked.
• An AI agent is not the underlying model itself.

What should you do?

1. Use a separate identity for every workload and every high-impact agent.
2. Avoid running background automation through a human account.
3. Link each identity to a purpose, owner or sponsor, environment and lifecycle.
4. Where appropriate, prefer short-lived or managed credentials to long-lived static secrets.
5. Record tool, model, runtime and agent identities separately.
6. Apply least privilege and review access regularly.

How do you audit it?

• Is the identity classified correctly?
• Is a non-human workload using a human account?
• Is the owner or sponsor current?
• Is a static key being used unnecessarily?
• Can the relationships among the agent, model, tools and runtime be traced?
• When the identity is closed, are its permissions and secrets closed as well?