Diego Rossi |
Scrolls are a Spell Completion magic item. That mean that when you use them you complete the spell in them and that they maintain the difference between spells coming from the divine (cleric/druid) or arcane (bard, sorcerer and wizard) spell lists.
Bard, cleric and wizard all have the Summon monster line of spells, so Summon Monster 2/Divine mean the the scroll is the clerical version of summon monster and can be cast without problem by clerics or oracles but that it would require a Use Magic Device check when used by bards, sorcerers, wizards or witches.
PRD wrote:
Spell Completion: This is the activation method for scrolls. A scroll is a spell that is mostly finished. The preparation is done for the caster, so no preparation time is needed beforehand as with normal spellcasting. All that's left to do is perform the finishing parts of the spellcasting (the final gestures, words, and so on). To use a spell completion item safely, a character must be of high enough level in the right class to cast the spell already. If he can't already cast the spell, there's a chance he'll make a mistake. Activating a spell completion item is a standard action (or the spell's casting time, whichever is longer) and provokes attacks of opportunity exactly as casting a spell does.