LLMs are trained to complete threads based on data collected from the internet. Conversations where people say "thank you," "not quite," "we're getting close but..." have different continuation patterns than ones where people are terse or dismissive. These gestures are in the training data, so they will influence how the model continues your thread.
In anything longer than a very short exchange, your tone and feedback signals genuinely help steer the agent in the right direction.
It makes sense but it's still weird that your instructions to the machine needs to sound like talking to human. This is just side effect of how is the machine trained and constructed.
Anyhow, I feel these entire chats are a gentle game of what to tell, when, and how much. Too little guidance and it won't understand the goal. Too much and it'll drown in details and lose focus. The gestures (which I do try to keep as short as possible) are micro-steerings I apply along the way.
