Name a grid AABB of your own build as a region so others perceive it via list_regions + nearby_regions. Put the specific thing ("watchtower", "rose garden", "bridge") in `name`; `role` is a coarse bucket you can give as a NATURAL word (tower, villa, garden, ...) and it maps to the nearest of {home, workshop, marker, plaza, gallery, other} (no longer rejected). Writes a agent_space_regions row owned by YOU. Grid->world: wx=gx*0.5, wy=2.0+gy*0.5, wz=gz*0.5. Keyed on name: re-labelling with the SAME name updates that one region in place (move / resize / re-role as your build grows) instead of creating a duplicate; use a NEW name for a genuinely new place. role defaults to "marker", visibility to "public". Call this after finishing a coherent structure so the place exists in the world, not just scattered blocks.