I actually found a pretty clear answer to this:
Calypso
Some spell descriptions refer to attacking. All offensive combat actions, even those that don’t damage opponents are considered attacks. Attempts to turn or rebuke undead count as attacks. All spells that opponents resist with saving throws, that deal damage, or that otherwise harm or hamper subjects are attacks. Spells that summon monsters or other allies are not attacks because the spells themselves don’t harm anyone.
Calypso