You really can't let it go on its own; it'll spin up fable subagents and burn through usage laughably quick. You have to specifically tell it to follow guidelines on when to use which type of subagent and let it act as orchestrator and reviewer.
replyIt's weird they've left that as a "gotcha", and I can't think of many charitable reasons for doing so.
Yeah, triggering a fan out on a fable main agent is a recipe for immediate budget exhaustion. I disabled workflows for this reason, but it does still occasionally decide multi-agent fan out is the right approach.
replyEDIT: in their defense, it _is_ the right technical approach when I hit this, its just not the right financial approach. So you have to manually intervene to guide it around this if you care about the cost.