These texts state that each demon (and there are a host of names and their abilities available) is responsible for his own abilities. No two demons are alike. And in order to summon one, you need to be able to recite the proper incantations.
Here is the diagram which needs to be drawn. The summoner stands in the centre of the circle, whereas the demon will appear in the triangle -- and will be unable to leave said triangle without the bidding of the summoner.
To call the demon forth, the summoner uses a chant (I've been told to recite it in Latin, not in English as the translation here states it) and after a complex series of speeches to welcome the demon and request its aid, all found at the site, the summoner then recites another chant to dispel the demon back to its plane of existence.
Whether or not you decide to base your demon lore on Solomon (as opposed to another religion or one of your own creation), it is an interesting read.