I have run into this credit disappearing act too, Agent keeps looping when it gets stuck on something it cant solve. I tell it that it is looping and to stop. I did this several times and finally it does stop. I gave it instructions not to loop and stop at 50 credits on tasks and to ask for permission to continue but this does not work. I keep an eye on my credits and you can see it dropping like a rock at times. The other time I had this problem is when I apparently misconfigured instructions to eventually send out warm up emails on a new email address. It drafed 350 emails before I saw it and stopped it. Again, would be great if it followed instructions on credit caps so you can catch problems early. Engineers need to fix this and (again looping) add this safeguard option. Worst case, you do have the option to simply disable the agent.