Adding or deleting a description for a specification template can be done in the Specification secondary tab in the Requirements primary tab. Click on the desired template to open up the details window. In the right of the details window, click Edit to start the editing mode. If the Description box is not visible, you may need to click on the description icon to expand the section.
Note that when a specification template is originally saved, there is also an option to add a description at that point.
Users will need public view and edit access in the requirements module to perform this action.