What it does
Model a custom weapon, tool, block or piece of furniture in a real 3D viewport, or import what you already made elsewhere, and export it in the exact shape the game needs to load it. The tedious half of custom Minecraft content is not the modelling, it is the config that has to be correct in four places at once.
Describe an item in a sentence and it comes back as geometry, a pixel-art texture and the configuration to install it, ready to be edited by hand rather than accepted as-is.
How I know it works
139 checks driving the export pipeline headlessly, and 34 more that launch a real application window and drive it through the interface. The second set is the one that matters: a pipeline can be perfect while the button that starts it does nothing.