First, apologies for the direct email. I'm emailing you directly as you've been listed as the update contact in one or more AppData files. In the software center we allow the user to search using case-insensitive keywords, for instance searching for 'excel' could match Libreoffice Calc or many other free software spreadsheet applications. At the moment we use the translated keywords set in the desktop file, any extra <keyword> entries in the AppData file, and then fall back to generating tokens from the name, summary and description using a heuristic. This heuristic works most of the time, but a human can often do much better when we know what the most important words are. I've noticed your application does not have any manually set keywords and thought I should bring this to your attention.
So, what do I want you to do? Basically, I would like you to add some keywords in the banshee.desktop file or the banshee.appdata.xml AppData file. If you want the keywords to be used by GNOME Shell as well (which you probably do), the best place to put any search terms is in the keywords section  of the desktop file. This can also be marked as translatable so non-English users can search in their own language. This would looks something like Keywords=3D;printer; (remember the trailing semicolon!)
The alternative is to put the keywords in the AppData file so that they are only used by the software center and not the desktop shell. You can of course combine putting keywords in both places. The AppData keywords can also be translated, and would look like this:
Of course, you don't have to do a release with this fix straight away, and if you have a stable branch it would be a good thing to backport this as well if it does not add translated strings or you have no string freeze policy. Nothing bad will happen if you ignore this email, but please be aware that matches from keywords are ordered higher in the search results than other partial matches from the name or summary. You also don't have to add keywords that are the same as the application name or package name, as these are automatically added as case insensitive search tokens.
When you've changed the file(s) and committed, please email me back and I'll mark your application as completed. If you don't want to hear from me ever again just edit the <update_contact> in the AppData file and change it to somebody else. I'm not planning on emailing more than once every 6 months, so don't worry about me spamming you with even more work to do. If you don't add the keywords then your application will still be visible in the various software centers, but it may be harder to find.