Blender's command UI is brilliant, because of its flexibility and ease of use. In this example using the Bevel command, you can toggle various tool options, such as width, segments and mitering with the press of a button.
The various options are listed on the bottom toolbar with their associated keys.

I could see this as complementary to the caddy, in which the buttons toggle context sensitive options in the caddy. The idea here is to reduce the amount of (redundant) modeling commands and cleanup the UI simultaneously. Other commands such as Step Build would benefit from showing the various hotkeys in a similar toolbar.
Disclaimer: The fact that this requires further context sensitivity of keyboard shortcuts is not necessarily the purpose of this idea! And should be voted for seperately here.