Horizontal surfaces are a trap! Working at a bench often leads to having tools spread all over the work surface, leaving no more real estate to do the actual work. A tool well for the workbench is a good idea because it gives a place to push tools aside while not in use. The problem with this is that chisels have sharp edges, and it you simply shove the chisels into the tool well, there is a good chance the sharp edges will clash into each other. A tool wall is good to store tools while not in use, but while actually working, the wall is a little too far away. The bench tool caddy solves all of these problems while only taking up a small amount of real estate on my bench.
I setup my tool caddy to always hold my mallet and marking knife, four Narex chisels, two marking gauges, vernier calipers, rulers, brad awl and a flush cut saw. These tools are often needed constantly while working at a bench. There are extra slots available for the not so commonly needed tools such as carving chisels, or any other specialty chisels I may use from time to time.