At the moment it searches only the title & description field.
It is debatable if it makes sense to search in the tags since you can filter them.
The search as it is now is is quite simple - but should cover the urgent needs (search in title & description).
But of course I'll plan to add more features to the search e.g.:
search other fields like (categories, exif,...), add logical operatores (and, or, not), weight the search results, add more options to refine the query (date range, search within categories,...).