My experience with opus/fable is somewhat different - they CAN reject something, but it has to be phrased very deliberately.

It's a bit annoying honestly. I'm always very careful to be incredibly neutral on the direction of a request, and I'd say 10% are knocked back on on valid grounds, which is great.

On occasion I accidentally say "let's do this" and it blindly goes and does it - I spent 2 days undoing something I built that was just a truly awful idea, because I accidentally phrased it lightly as a request, not a discussion!

I have a similar experience with GPT 5.6 sol.

Nowadays I often prompt like "I heard there is also this different direction, what do you think about that?"

Another thing I do is asking the agent to make a decision matrix for choices. It's useful to discuss, give feedback on, and signals that it's a discussion, not a request for a particular direction.

It's then also easy to say: create a prototype for multiple directions so I can compare the solutions.

That way I choose the problem, I choose the solution, but the agent can help me discover solutions, make tradeoffs visible, and implement solutions.