I need to have a closer look at this. Mostly because I was surprised recently while experimenting with making a dieting advice agent. I built a prompt to guide the recommendations "only healthy foods, low purines, low inflammation blah blah" and then gave it simple tools to have a memory of previous meals, ingredient availability, grocery ticket input and so on.

The main interface was still chat.

The surprise was that when I tried to talk about anything else in that chat, the LLM (gemini2.5) flatly refused to engage, telling me something like "I will only assist with healthy meal recommendations". I was surprised because nothing in the prompt was so restrictive, in no way I had told it to do that, just gave it mainly positive rules in the form of "when this happens do that".