For chainline adjustment, I'd definitely recommend getting two of the tools and two big adjustable wrenches. For simple tightening/loosening, one will do w/ British threading (two necessary w/ italian threads because one will loosen as the other tightens.) If your LBS knows what they're doing, they used blue loctite on the threads, so if it's set (which it has by now) it's best to take them all the way out, clean off the threads, and reapply a few drops of the blue stuff.