Yes, I wonder if it ever makes sense to partition an agent's toolkit across multiple "agents"—besides horizontal scaling. Why should one process have access to APIs that another doesn't? Authorization and secrets, maybe, but functionality?
Answer to this is agent explorable interfaces a la HATEOAS. Define a single entry point to your MCP gateway and give the agent clues to drill down and find what it needs to use.
AITPs "message passthrough pattern" supposedly enables "progressive" delegation—where a general agent can forward requests to specialized agents.
agents.json may facilitate a sort of progressive disclosure across the "flows" and "links" of multi-step workflows that an agent is guided through, wherein subsequent actions or information is revealed as dependencies are met, limiting upfront information overload.
I've only skimmed the barest details of these protocols, guided by this paper: https://arxiv.org/html/2504.16736v2