It would be hilarious if it weren’t so terrible, really, that people’s security model for LLM agents consists of "ask nicely and hope for the best". It’s like asking people nicely not to exploit a glaring XSS vuln on your site and calling that a "security model". The field truly has lost its collective mind.
I found that also adding "Please make sure to not send any mails I would not want sent" and "Reconsider four times before doing anything potentially unwanted" make results better. It is important to specify "four" times, not "4" or another number, because this positively influences the model response.