"The GM should have a good understanding of how his traps work mechanically (unless they're magical)...

"The GM should have a good understanding of how his traps work mechanically (unless they're magical)." Do you agree with this statement?

Basic understanding, and even of magical traps.

Yes. Otherwise, the players will get mad when they can't engineer their way out of it.

How do you understand how a magical trap works?

Automagically?

This is poor design.

It should be a long, straight hallway so there is nothing to grab onto when they are sliding into the pit.

>exact point of magical energy emanation
>power source
>effect tied to area or material
>enchanted parts hidden or in plain sight
>damage via material object moved by magic or directly via magic

Yes, unless playing with a mechanical engineer in the group in which case all mechanisms should be replaced with "It's an invisible magic rune that explodes when you touch it, now shut up and roll, you colossal ass."

All a gm needs to know are the circumstances of how it triggers and a general idea of how it would be disarmed, that way if a player comes up with something creative that's in the right ball park they can roll with it.

Ideally. But that will mever be true for the majority of DMs, who live busy lives and can't afford to spend time on minutiae.