detailed_background should be tagged if the setting ('forest', 'kitchen', etc) can be determined from the background. Even if the background is sparse. This is also tagged for photo backgrounds, etc. Note that this does not reflect on the artistic quality of the background. The background is detailed if you can determine the setting from it, even if it is a shoddily done sketch.

amazing_background is an additional tag for the extremely detailed backgrounds.

simple_background should apply only rarely to this search, but is included for the cases where sand, moon, stars and so on appear on clothing etc instead of on background.