Forge UI Modifications: How to force users to add extra text beyond a prefilled template in the Description field?

In my Forge app, I’m working with Jira UI Modifications.
I can successfully prefill the Description field with a template value using onInit.

But my question is:

I don’t want the user to just save the issue with only the prefilled template.
I want to force the user to add some extra text into the description field before creating the issue.

Basically:

  • Prefill description with a template (e.g. “Steps to reproduce:\nExpected result:\nActual result:”).

  • If the user doesn’t add anything beyond this template, show an error and block issue creation.

Is there a way in Forge UI Modifications to validate that the description contains more than just the template text, and prevent saving until the user adds additional words?