Is there any way to add text or modify the information displayed on the authorization box that appears when a user has to enable a script?
In its current form the box is far too terse for my users to stand any chance granting access to the script. This will be deployed on an internal domain space.
Unfortunately there is no way to customize the authorization dialogs at this time.
When I roll out scripts for organizations, I usually send a brief introductory email that includes a list of instructions on how to access the tool, and I include a mention of the authorization process in that list. I've had good success with users by taking that approach.