Re-reading, I’m guessing the prompt could also be dynamically generated to include the most relevant delegates.
Yup that's how I'm doing it - the system prompt is re-generated for every request, and that includes getting a list of available delegates and the arguments they accept. I only have 10 so I'm just listing all of them, but if you had some huge number you could combine that with embeddings / vector lookup.
In the case you describe, you can have an LLM write the tools.
Yes, the first tools and bridge code might need to be manually built. But after that it could be LLMs all the way down.
Kind of similar to writing a new programming language. At first you write it in another language but after compiling it for the first time, you can then write the language in the language itself.