The only secure way to use any of these tools is to give them very limited access - if they need a credit card give them a virtual card with a low limit, or even its own bank account. They can send email but only from their own account; like a human personal assistant. But of course this requires careful thought and adds friction to every new task, so people won’t be doing it.
I'm using the signal-cli-rest-api but the whole setup feels kinda wonky.
Nanobot's was not great (cron + a HEARTBEAT.md meant two ways to do things, which would confuse the AI). But because the implementation is so simple, I could improve it in a few minutes in my own fork!