STEP-BY-STEP
1. Please go to create a rule in Advanced Options --> Settings --> Rules:
2. In such Rule, you will choose the trigger "When an action is assigned to a user" and add a logical condition that says "Internal ID is X" (this X is the ID for the specific Action who will trigger this), to find the X just go to the Action Item and click View, now look at the URL as seen below highlighted:
Now that you know the X set the trigger as specified above.
3. In the section "What does it do" add an Action "send a notification to the user".
4. Now edit the action as you see below, especially set the user who will receive the notification "[[Assignment.Assignee.Id]]", also in the body of the message you can use tokens like:
"[[Assignment.Assignee.FirstName]], your instructor wants you to succeed! Please visit a success coach in the Student Center"
.