It is almost comically bad. I've had a few simple parts to design for 3d printing in the last weeks and tried it with them (each are about 4 operations on the timeline), and it never created close to what I was trying to do even if spelled out step by step according to Fusion naming.

At this point I'm not even sure if it can properly create a simple primitive solid.

Have you yet tried the Fusion MCP that was launched last month? https://aps.autodesk.com/blog/bringing-fusion-claude-creativ...

Still a long way to go, but I'm sure it will get there eventually.