I'm not following. There are way more tools in the world, and likely available on every machine, than can fit in any model context. One can create a small list, but that will be very org dependent. Programming is very open ended, I struggle to see the 'deterministic set of choices' here.
I'm looking at Jev/Kev like models for some control over tool calling and similar, but I also think that fine-tuning out behaviors (like qwen 3.8 wanting to use rkt all the time) may be better in the long run. Instead of having to check/change every tool call, we can refine the main LLM to have high enough likelihood of using the tools we actually have, that we won't need to check every call.
Jev is definitely useful, but also being held like a hammer in search of a nail right now, approaching OpenClaw like fanfare and hype levels. No one talks much about OpenClaw these days, I would not be surprised if Jev has a similar trajectory.
The whole point of Jev/Kev is efficiency. If you can make decisions faster, cheaper, and more reliably that's the benefit. Even within the model architecture itself, you could use a classifier as a router within MoE to pick the expert that's likely to give the best outcome.