Some tools when added to modelbuilder have 2 or more outputs, a good example is the Select Layer By Attribute, you have the layer with the selection and a count of the number of selected.
Often I do not need to use the count and I find it clutters up the model. It would be nice to be able to right click on it and hide it. This is opposite to right clicking on a tool and exposing a parameter, within the model. So at the moment we can expose parameters but we cannot hide derived outputs when not needed.
