The switch from plan mode to build is not always clearly defined. On a number of occasions, I've been in plan mode and enter a secondary follow up prompt to modify the plan. However, instead of updating the plan, the follow up text is taken as approval to build and it automatically switches to building.

Ask mode, on the other hand, has always explicitly indicated that I need to switch out of ask mode to perform any actions.

This is my experience with Cursor CLI.