I'm only running a few agents in parallel so far, but I don't let them write or read anything w/out my approval. This slows things down quite a bit, but it mean

I'm only running a few agents in parallel so far, but I don't let them write or read anything w/out my approval. This slows things down quite a bit, but it means that I have exactly the opposite of your problem of stopping them. I've only started really thinking about developing my own harness, but one of the reasons would be to implement some mechanism where I could give the agent a "turn budget", say, 5 turns, when I can clearly see what the agent is going to be doing for the next few turns, without my needing to allow each turn to go forward. But it sounds like the same thing would be useful for you as well, just in the other direction. Could you say more about what "certain points" you're trying to get them to stop at?