Help button/icon similar to unitys help icon/button

It would be very helpful if each node had a mini help menu button. It could be similar to unitys little help icon which is located at the top right in the inspector of each component. Once activate it would show a little comment window at the base of each node which tells what the nodes does and what the input and out puts are for or you could have a section at the mid bottom of the graph editor which has the comment there when a node is selected.