Blind Defence - SB with A9o

5/10 at Party. I'm in the SB with A9o, a 25/18/2 RFI on the button. The BB is 30/3/0.4. Nothing unusual sticks out from their play, and my image should be as a TAG also. I have no other reads.

This is my thinking:
Against any BB this would have to be played as a raise as opposed to a call. Therefore against a tighter BB you would be more inclined to play this hand.
I would easily raise ATo.
I would easilty fold A7o.
I may raise with A8s.
I may call with A6-7s
I would fold A5s.

So what do you think? Marginal between fold or raise? And how about my thinking?

Trent.