[Extunarian]

I don't have access to the current emu source that p1999 uses, but the public EQEmu code that p1999 was built from used agility and level differential to determine whether or not a hit landed. Once it was determined if the hit landed, AC/Defense was used to determine how much damage would be mitigated.

So yes, agility does help avoid a hit outright, but you should also take into account how much higher/lower in level you are compared to what is trying to hit you.

And warriorman is correct: AC gained from increases to agility should not contribute towards the soft cap on Worn AC.