This makes intuitive sense. Can I ask what harness you're using that allows you to configure the constraint and how?
You can do this in opencode and pi (haven't used), by defining your own agents or overriding the built-in ones, so in your primary agent you can disable all tools and give it good instructions for how to delegate
I imagine most harnesses should have a way to do this today, if they don't, get a new one. OpenCode i.e. is highly customizable, Claude and VS Code both support a ton as well including custom agents (though unclear if you can create custom top-level in claude-code)
https://opencode.ai/docs/agents/
https://code.claude.com/docs/en/sub-agents
https://code.visualstudio.com/docs/agent-customization/custo...
It's a custom agent loop. There are no other parties involved here. Just vanilla C#/.NET and the OpenAI DLL.