While I see where you are coming from... It's not about your personal autonomy, it's about perception. You can be completely honest and people still perceive you as dishonest. In fact, absolute honesty is often perceived as rudeness by skilled negotiators. It took me a long time to grasp this - it's much better to deliver a message than be honest, although being honest AND delivering a message is even better (and the article talks exactly about that). And the message being delivered is often not the bare meaning of the words. Unskilled negotiators often deliver the wrong message (I have been there so many times...), although they used the most precise words while doing it.