This post reads like it was written by a Common Lisp fan who is looking for a reasons to say that Common Lisp is good for AI agents, rather than an AI agent user evaluating what languages are really best.

I've heard fans of both statically typed and dynamically typed languages advocate for their language. The static type fans say that the rigorous compilation process gives the LLM a fast iteration loop with clear messages from the compiler on what invariants aren't being upheld. The dynamically typed languages advocates talk about fewer tokens, the popularity of the language in the training data, and so forth. Guess what, these are the exact same arguments these communities made for human developers.

Personally, I don't know the answer. The industry has swung back and forth on this over the decades. Before AI code-gen static languages were on the upswing for a variety of reasons, including runtime efficiency and much better ergonomics thanks to modern type inference engines. I suspect those reasons are still valid, and also that statically typed languages give LLMs a leg up because it is easier to reason about them locally thanks to declared types and information hiding.

Yeah, I mean it's tough to describe how good it is to use agents with a lisp REPL, but it's really great using agents with a Lisp REPL.