Removing the action nodes from the System Fallback topic is a UI-only change that can be done in minutes, needs no code or flow redeployment, and immediately prevents any write operation when fallback triggers. The fallback topic continues to log missed utterances, allowing later tuning, and the edit can be applied identically in test and production to keep behaviour aligned. Because the write action is physically absent, recurrence is impossible, fully satisfying the requirement.

A. Temperature affects wording, not tool invocation; write calls remain.

B. New connector breaches “no redeploy/no new components” and does not stop current flow.

D. Adding approvals slows but still allows unintended writes and requires policy work in every environment.

1. Microsoft Docs – “Edit topics in Copilot Studio”, Removing or disabling nodes section.

2. Microsoft Docs – “System fallback topic behaviour”, Logging missed utterances paragraph.

3. Microsoft Docs – “Copilot Studio governance: ensuring write actions only from explicit intents”, Best-practice note on removing actions from fallback.