or Make Assembly from Part
Did you really mean this? Do you want the part desription copied to the assembly description, or did you mean to say "Make Drawing from Assembly"?
If so, I really don't think you're going to be all that happy with a macro. Ideally it should be a little bitty add-in. The macro version would have to be run once during the SW session prior to creating any new drawings. The reason is that it has to be run in order to start watching the user's actions and monitoring for events. You can, however, add parameter switches to the SW shortcut on your desktop to force it to run a macro on launch.
Also, there is no event for "Make drawing from part" or assembly. That's not really what you want anyway. What if the user creates a new drawing by choosing File->New? What needs to happen is that when a new drawing view is created (any new view), the macro will catch that and check the drawing's custom properties for existence of the "Description" property and whether or not it is filled out. If no data exists, the macro copies it from the referenced part or assembly.
Maybe someone here will write that macro for you for free, but I sort of doubt it. The motivation is minimal. There are requests for macros here all the time. Personally, I've written quite a few and posted them. However, the task has to meet some combination of these criteria:
1. The challenge is interesting, leading me to investigation of a new area of SW.
2. It's a macro that I perceive could be useful to multiple people.
3. It's a relatively simple modification of one I've already written.
It also helps when it's not a direct request by a poster for someone else to do all the work for him/her.