If Announcement tool is hidden, student can not click on the announcement widget link to display the announcement.
Hide announcement tool from student view
Add an announcement to your site that is released to a group
In Lessons, add announcement widget
Impersonate student in the group that should have ability to view announcement
Go to lessons and select the link for the announcement. The page either refreshes or sends the student to the Overview tool. The synoptic tool on overview page displays the following: