You can have agents that serve multiple different users with varying levels if permission

Anti-pattern imho. Agents should operate within granular identity and permission scopes, with audit and log trails for all data operations (read, write, etc).

Copilot: https://learn.microsoft.com/en-us/entra/agent-id/identity-pl... | https://learn.microsoft.com/en-us/purview/audit-copilot (for example)

TLDR Maintain an identity boundary whenever possible.