Request a draft with a clear boundary
Describe the recipient, purpose, facts that must be included, and tone you want. State explicitly that the agent should prepare text only and wait for your review before sending. If the message needs an attachment or a particular subject line, include that in the request so the draft is complete enough to assess.
For sensitive or consequential messages, ask the agent to identify any assumptions it made. Check names, dates, figures, promises, and links against the source information. A fluent draft can still contain a mistaken detail, so review the actual content rather than approving it because the wording sounds polished.
Approve the final message separately
When the draft is ready, edit it yourself or give specific corrections. Before allowing a send action, confirm the recipient address, subject, body, and attachments. A message intended for one customer can have a very different effect if an address is mistyped or a private file is attached.
Keep a copy of the final version and any important approval context according to your normal recordkeeping practice. If the task does not require sending, say so directly; there is no need to grant permission for an external action just to receive writing help. This separation preserves your control over the final communication.