I have met countless of people whom I group with that don't know why their AA doesn't work. Anyways, I think it would be great if you could interupt the AA if the person doesn't have the scroll memmed. Then they can say, "Why is my AA not working" and we reply buy the dang scroll and read the AA description. Right now they use the AA and nothing happens. Many of them just think that the AA such as slow or malo gets resisted all the time and uses another spell.
That works great, until it's a spell from a lower level that they added during some recent expansion. This is a reasonable and simple request, there's no reason for it not to be.
The problem is buying an AA without reading the fine print. Not unlike routinely agreeing to an EULA without ever reading it.
Perhaps instead of a message, an aa rank for these aa lines can be blocked from purchase if the character does not have at least one spell in their spellbook that would trigger from the aa? If someone later deletes a spell from their spellbook . . . that's on them.