Invisibility ends early if the invisible entity attacks, casts another spell, interacts with an object, takes an action or bonus action, or is damaged.
This is probably the best tool to scout safely, as long are there are no creature with See Invisibility, which is fairly rare. One can scout an entire area thanks to the Mage Hand's Fly which makes it able to go to places otherwise very difficult to reach, as long as one can make the camera see the ground level of that place.