That "deep dive" is an apples-to-oranges comparison. MCP is also a "HTTP API" that you so criticize.

You also somehow consistently think LLM making tool calls against an OpenAPI spec would result in hallucination, while tool calls are somehow magically exempt from such.

All of this writing sounds like you picked a conclusion and then tried to justify it.

There's no reason an "Agentic OpenAPI" marked as such in a header wouldn't be just as good as MCP and it would save a ton of engineering effort.