Least access, approve the risky bits
Least access
Connect only what the task needs. A research agent doesn't need your email. A calendar helper doesn't need your files. Where a connection offers read-only access, take it. Point file tasks at one folder, not your whole drive. Every extra connection is one more thing that can be misused if the agent misreads or is misled.
Approval gates
Most agent products let you require approval before certain actions: sending messages, making purchases, submitting forms, deleting, sharing files or changing settings. Turn these on. A good agent shows you what it is about to do, in full, and waits. Approving takes seconds; undoing a sent email or a payment may be impossible.
Logins and take-over
When an agent reaches a login, payment or security screen, the safer products hand control back to you so you type the password or approve the payment yourself. Don't paste passwords into an agent chat, and be wary of any tool that wants to store them. Use your password manager and two-factor sign-in as usual.
Separate where you can
For experiments, use a separate browser profile, a test folder, or a secondary email account with nothing important in it. At work, use the agent your employer has approved, under its controls. Separation means a mistake stays small, and it makes it obvious which actions came from the agent.
If an agent connected to your email made one mistake on your behalf, what is the worst it could send, and to whom?