[csemple]

You're exactly right—treating the LLM as an untrusted user is the security baseline.

The distinction I'm making is between Execution Control (Firewall) and Cognitive Control (Filter).

Standard RBAC catches the error after the model tries to act (causing 403s, retry loops, or hallucinations). This pattern removes the tool from the context window entirely. The model never considers the action because the "vocabulary" to do it doesn't exist in that session.

Like the difference between showing a user a "Permission Denied" error after they click a button, versus not rendering the button at all.

[XenophileJKO]

As someone that has built many of these systems, it doesn't remove the tendency or "impulse" to act. Removing the affordance may "lower" the probability of the action, but it increases the probability that the model will misuse another tool and try to accomplish the same action.

[csemple]

Ya, makes sense—if the model is trained just to "be helpful," removing the tool forces it to improvise. I’m thinking this is where the architecture feeds back into the training/RLHF. We train the model to halt reasoning in that action space if the specific tool is missing. This changes the safety problem from training the model to understand complex permission logic to training the model to respect a binary absence of a tool.

[ramon156]

You're absolutely right!