A Summoner, like most mages, has limited options for their weapon of choice. They may choose from Club, Dagger, and Staff. Their skills in those weapons are rated at C, E, and B respectively. The dagger is a Summoner's weakest weapon and is also the least suited to boost their abilities. Although they have a higher attack speed than our other options they are generally weaker as well. Unless you are fighting very weak enemies or are intent on raising this skill I advise against using daggers.