Been saying this for a while and mostly getting blank stares. In-context "controls" as the primary safety mechanism is going to be a bitter lesson for our industry. What you want is a deterministic check outside the model's reasoning that decides allow/deny without consulting its opinion. Cryptographic if the record needs to survive a compromised orchestrator, and open source. If your control is a string the model can read, the model can ignore it. If it can write it, it can forge it. I'm surprised how strange that idea sounds to some people.

Disclosure: I'm working on an open source authorization tool for agents.