The problem with formal prompting languages is they assume the bottleneck is ambiguity in the prompt. In my experience building agents, the bottleneck is actually the model's context understanding. Same precise prompt, wildly different results depending on what else is in the context window. Formalizing the prompt doesn't help if the model builds the wrong internal representation of your codebase. That said curious to see where this goes.
Two pieces of advice I keep seeing over & over in these discussions-- 1) start with a fresh/baseline context regularly, and 2) give agents unix-like tools and files which can be interacted with via simple pseudo-English commands such as bash, where they can invoke e.g. "--help" to learn how to use them.
I'm not sure adding a more formal language interface makes sense, as these models are optimized for conversational fluency. It makes more sense to me for them to be given instructions for using more formal interfaces as needed.