In Planner add the ability to tag a teammate in the comment section of a task.
The ability to tag (mention) a teammate within a task in Planner to call attention to that specific teammate for updates on the task
Squigs Daddo commented
This is mentioned in many different requests. The need is clearly there. Please jump on this one to vote it up. https://microsoftteams.uservoice.com/forums/555103-public/suggestions/40726792--mention-in-planner-tasks-with-notification