Golden Legionnaire: Allied Retribution action type? [PFS]

[Sesharan]

The Golden Legionnaire ability Allied Retribution says:

Allied Retribution:

At 3rd level, if a Golden Legionnaire sees a creature within 60 feet of her attack an ally or any friendly creature, including herself, she can select that attacker as a designated adversary. When a Golden Legionnaire does this, she gains a +1 morale bonus on attack rolls and weapon damage rolls against the designated adversary for a number of rounds equal to her class level. A Golden Legionnaire can have a number of designated adversaries up to 1/3 her class level. If she already has her maximum number of designated adversaries selected, she can end the effects of her allied retribution against one of her previously designated adversaries when she selects a new one. The Golden Legionnaire can reselect a creature that is already a designated adversary if it attacks an ally or a friendly creature again, allowing her to restart the effect's duration.

Nowhere does it say what type of action it is to activate this ability. I assumed without ever really thinking about it that no action was needed, and that it was just something I declared whenever an enemy got off an attack. However, I used this ability for the first time during a PFS scenario last night, and my GM asked what kind of action it was to activate that ability- quite reasonably, since I had already used an immediate action and all my attacks of opportunity. I didn't have an answer for him, since I'd never thought about it. So we both looked at the description, and I said I thought it was an automatic reaction, but he reminded me that if an ability doesn't say what type of action is required to activate it, we're supposed to assume it's a standard action.

Now, I totally agree in every way with how my GM handled the situation, and played by his ruling for the rest of the scenario. But despite his convincing argument, something in the wording still makes me want to think that it works the way I originally believed. And if it doesn't, a standard action for a +1 on attack and damage against one enemy for me alone seems like a pretty terrible use of my time in most situations. So... am I just trying to make this ability more powerful than it's supposed to be? Or is there something both of us missed that explains how this ability is activated?

[Cheapy]

The ability is (Ex), so this is the rule that governs its action:

Quote:

Extraordinary Abilities (Ex): Using an extraordinary ability is usually not an action because most extraordinary abilities automatically happen in a reactive fashion. Those extraordinary abilities that are actions are usually standard actions that cannot be disrupted, do not require concentration, and do not provoke attacks of opportunity.

The rule the GM quoted is for Supernatural abilities only.

So...not an action!

[Grick]

Allied Retribution (Ex)

Extraordinary Abilities (Ex): "Using an extraordinary ability is usually not an action because most extraordinary abilities automatically happen in a reactive fashion. Those extraordinary abilities that are actions are usually standard actions that cannot be disrupted, do not require concentration, and do not provoke attacks of opportunity."

Since the ability is triggered by witnessing another creature attack an ally, and since that generally doesn't happen on your turn, I think that makes it a reactive ability and thus takes no action.

[Sesharan]

Awesome! I knew there was something I was missing. I really ought to take another look at that section of the rules. Thanks, all!