Tool already edits when using shortcut keys I'm sure this must have been thought out, but I find this behaviour really off-putting...so, let's use bevel as an example. In the supplied gif, I am first activating the bevel tool using the ctrl+B shortcut, but this immediately makes the tool active. It doesn't wait for me to press the mouse down. 
Yet, when I activate the same tool via the menu, as you can see in the gif, it waits for me to click.

Why is there this different behaviour between two ways of activating the same tool? If I want to use the shortcut key, I have to put up with a tool working in a way that I do not want?
For the shortcuts, that is always how blender worked. Since clicking on the tools on the left is just switching the mode, or what will happen when you click/drag (look at the select tool, then switch to the 3D cursor tool), you have to activate it to work. Hope this helps :)