I've had that looping issue with open models too. But never 4.1. I wonder if it's a model + harness combo? But yeah, one loop issue and I'm done with a model forever.
Yeah, that's what I'd been leaning towards.
No mcp, but I'll see if I can reproduce and debug it, since other people don't seem to have that problem as badly as I've experienced it (and the idea of having a nasty bug like that bothers me).
No mcp support.
I'll try copying deepseek harness's basic tool call formats as a starting point.