the main agent would be very different, basically an orchestrator, and you are "loop engineering" it, and turning off all the things for this main agent besides being able to run subagents
for opencode:
https://opencode.ai/docs/agents/#permissions (what tools, mcp, etc...)
https://opencode.ai/docs/agents/#task-permissions (what subagents it can call)
https://opencode.ai/docs/agents/#additional (thinking effort)