Ah, so it a "smart" retry mechanism?

I'd like to think so! ;). It has some brains, but the key insight was to send the model domain-agnostic nudges. I don't need to know what you're trying to do, the LLM already knows, I just need to nudge it back on the structural side: text response vs tool call, arg mismatch, etc. and let its knowledge of the context fill in the blanks (otherwise I'd need a massive library of every possible failure mode).

The other insight was doing it at tool call level and not workflow level, which addresses the compounding math problem more directly.