You can create one UseCase Description per UseCase.
There are three built-in templates for UseCase Description so that you can choose the one to match your clients.
Also you can create your own templates.
There are two ways to create UseCase Descriptions.
There are three default UseCase Description Templates.
Customized Template file will be saved as "UCDescriptionProp.properties" in the Userhome/.astah/professional(uml)" directory.
The customized template won't be saved in .asta file.
In order to share customized template within team, export the customized template and distribute it to your team members. Anyone who received the template file, they can import it into Astah to apply.