May run into your 3" length problem, but one of the best out there, IMNSHO, is a Gerber Guardian Backup.
Full tang, nice fully adjustable pull sheath, straight pull/no-flip - grab it & you have a blade = knife. Zip nada. A quick knife.
About $35+ - abouts. Why flip when you can drag out a blade?
& depends too on what you'd want = "social" or a thing to cut stuff sometimes.
Matters.
I've a couple SAK "mumble" li'l things always in my pockets that does a wonderful job for anything basic - slices things open, gots the "mini"-scissors & a cuopla other things & weighs in at about nothing. A very handy tool I'd never be without.
In my other pocket, I'll carry a bigger bladed SAK that is a bit more heavy duty, & with a couple extras.
I might carry that Gerber Backup sometimes.
I've never needed the "tactical kinfe."
I've carried it sometimes to "be sure" in some uncertain times - mostly, when extreme backpacking & the like. Very nice to be able to drag out a blade without having to flip anything - kinda like some of the better flashligths where you don't have to "ask permission" to get a light .....
If I need a "blade" in a "social experiement," please do give me my BHP.
It has better range, better depth. Then, knives are for sissys.