[3.5]Melee attacks into Antimagic Field

[Tanuki Tales]

Except you don't ever, by RAW, enter another's square to attack.

EX: A Hydra attacks a longsword wielding medium sized human 10 feet away. Said human can not, by RAW, ready to attack with a non-reach weapon, when it's head comes into your square to bite you. If you could, it would render reach far less useful. Perhaps justifiably so.

RAW, you don't enter the square, so your summoned creatures can and do attack just fine. Doesn't make logical sense, but welcome to D&D.

But the AMF states that Summoned creatures and incorporeal creatures who enter an AMF blink out of existence.

The discussion isn't whether the monster enters the PC's square but whether the Monster with Reach can attack the PC who's inside the AMF while the monster is outside of it.

Edit: But that's concerning the Action Economy, which we aren't discussing here.