a lot of nail polishes have formaldehyde so yeah, the glue won't hurt. it will keep it from splitting too far down and that will hurt.

so look un*touchable, if it's a one-off, do all these things- hold it with glue till its long enough to trim the broken bit off, get some cream or liquid for brittle nails, look at your diet and make sure you're getting enough calcium and other nutrients that lack of can affect hair, skin and nails.. but if it happens to more of your toesies, do get it checked out by your doctor, there won't be anything scary wrong, but you could have a fungus (i know, ew) but they can fix that for you.

call the hospital and see what you should do! don't glue anything just yet!!!!!!! call a doctor or something

this sort of thing happened on my pinkie toe (and it hurt like a *****), so i just wrapped it up in bandaids for weeks. but i think you should call a doctor

Just do nothing. It will heal itself.