Catch Off Guard and Armed / Unarmed distinction

[Creamsteak]

Most of the time, this feat and the explanations I've read for it seem fairly clear cut. If someone has a weapon or natural attack of any kind (including gauntlets for most medium or heavier armors), they are considered armed. My question primarily deals with archers.

Is a humanoid NPC holding just a longbow/shortbow/crossbow/sling considered armed? What if they have no ammunition to use the weapon?
If not, what about if they have an arrow in one hand (as an improvised melee weapon)?

I also assume wearing a (non-spiked) buckler is not armed (can't be used for shield bash), but other shields count as armed.

[Avianfoo]

I think a better question is when is someone unarmed? Clearly when they have no weapons in hand. Including improved unarmed strikes. Effectively this feat is only really useful (barring removing the penalties on using improvised melee weapons) on the first round of combat when weapons have not yet been drawn i.e against seasoned adventurers wearing armor spikes and gauntlets: very rarely. But very useful against a wizard that almost never draws a weapon.

There will be grey areas (like do improvised weapons count as being armed? When does an item start actually being an improvised weapon?) but that is what the GM is for: to make rulings in those situations.

The intent of the feat is pretty clear: an unexpected swing with some random object which causes the target to be flat-footed. The weakness of the feat imo is that it doesn't really make sense for the target to be continually flat footed after the first attack (nevermind the third or fourth...stop hitting me with that tankard...again?..again!?..was not expecting that.). Also it makes even less sense that just because you are wearing gauntlets you are immune to being surprised by a table leg to the head.