Thanee
First Post
Note, that Arcane Sight does not require concenctration, discerning the school is part of the effect as per the Dispel Magic description. IMC this is done automatically, no action or effort required.This spell makes your eyes glow blue and allows you to see magical auras within 120 feet of you. The effect is similar to that of a detect magic spell, but arcane sight does not require concentration and discerns aura location and power more quickly.
Otherwise, Arcane Sight is limited to your own sight radius, as you said, but it does make the magical auras visible for you, since it allows you to see them.You know the location and power of all magical auras within your sight.
It's not hard to guess, that someone or something invisible must be approaching, if you see a bunch of magical auras closing in, where you cannot see anything else.

Bye
Thanee