Hi Rajeev,
There are specific action blocks for all kind of operations you do on the MII admin screens i.e. Read, Write, Delete, Transport. You can search for these in the UME section of Netweaver.
Try to search with screen name like "*AlertManager*" for actions related to Alert Manager screen.
So you can create roles with the specific actions for specific admin screens so that user has only the required access.
Regards,
Rohit Negi.