Art and add-ons
Generated art is the default. Library packs are something you import on purpose.
Generated art
Visual art for a new game is made for that game. 3D orders real meshes. The plan names what should exist; the repair pass is where those files are supposed to land in the project so the player actually sees them.
A rich 3D request should not come back as four hero meshes and a field of untextured boxes. If that happens, say so in chat and name the missing props.
Add-ons
Studio Add-ons searches a CC0 corpus (sprites, packs, ambient textures, and similar). You import on purpose. The first-build prompt does not mandate library art, and a Godot game must not point the player at raw library URLs for what they see.
Sound
Audio is the exception. Clevoir does not generate music or sound effects yet. A plan can load an exact library clip the manifest prints. You can also upload audio yourself.