This is possible providing the following assumptions are true:
- The item edit operation is initiated through the Java API (eg. user could click a custom button which calls your custom app and that initiates the edit)
- A local integration point is used
- The Java integration exists on the user's machine (this won't work from a trigger script)
- The user must have the Integrity Client installed
Essentially, you would create the editissue API Command with the Option to set the field value of the Description field and also with the "gui" Option. Since the "gui" Option is used, the item edit will be presented to the user in a regular edit window with the Description field prepopulated. The field values that are set by the Java API are only saved if the user clicks OK or Apply and those field values can also be changed by the user (assuming proper editibility permissions etc.).
Please see the Integrations Builder Guide for more details.
Regards,
Dan Rusu