before_tool_callback can skip one tool by returning a dict. The agent callback is the admission check. Skipping one tool does not decide the rest. An allow list is a later check on the subject.
After the subject is known
| Check | Where |
|---|---|
| Bearer accepted | The hook on Google ADK |
| Allowed tools | Trust-store row, when your process enforces it |
| The action itself | Authorization using the subject |
Revoke in Agents stops new tokens when the subject is the OIDC client id. Tokens already issued last until expires_in unless a later check rejects them.
When the token is an RFC 8693 delegation, the person stays the subject and the agent stays the actor. Authorizing the agent as the user skips the delegation.
Related
| Read | To learn how to |
|---|---|
| Custom channel auth for Google ADK | Admit the caller |
| Enriching instructions for Google ADK | What the model is allowed to see |
| Authorization | Pick the check after the subject |