I don't know too much about the Routing module, but if it uses the principle of the welded construction module, this kind of data is stored in the section sketch file. It may be the same, with a "description" property that gives its description and is modifiable.
I didn't use the routing module too much, but wouldn't it be like for mechanical-welding: there is a folder with the list of parts (or bodies) in the shaft.
You have to right-click and from this window you can change the name (be careful, there are several tabs, for welded parts it's in the first one I think), I think you're talking about the description (field that you may need to add if it's not already present).