We also need to keep in mind that there are certain types of summons - I've put in a few spells for homunculi, which are effectively giving *life* to inanimate objects. They are closely related to Golems similiar forms of creatures that are "created" by mages but are most certainly not natural. Which brings in the "undead" and "unlife" category vs created life.
Those tend not to need binding spells or protection spells to deal with them as they are bound to the caster - not creatures pulled from somewhere else.
Though I do admire the "drop an angry elemental into the mass of troops" summon - especially if you have the foresight to enact a protective warding before hand
Or the always near fatal "Open a portal to another plane of existence. . . by accident."