I want to add a short description under the 'Summary' field. I have already added a description under the 'Summary' field on the customer portal form. How would I add it to the internal form? What I mean by internal form is the form that comes up when you click 'Create' to create a ticket in the Jira instance.
Fields visibilities can be restricted/modified with the help of screens.
In your case, you may need to add short description field on the create screen
(So that it'll appears while clicking on the create button on instance)