Is it possible to send notification only once when manager assigns employee goals?

Summary: We are seeking a way to only send a single alert to employee to an employee when manager assigns goals.

Content (please ensure you mask any confidential information):

Current scenario is manager assigns a goal and employee gets notification. 10 minutes later manager completes second goal and another alert is sent, etc.

We would like the employee to only be notified a single time when goals are assigned. How can this be accomplished?

Version (include the version you are using, if applicable):25B

Code Snippet (add any code snippets that support your topic, if applicable):