The rules for leaving Cozumel say "no tools" and the guy inspecting your carryon has no discretion to make a decision about how dangerous a certain tool could be on a plane.Confirming this... lost my allen key set that I keep in my SAD kit leaving CZM last year.
Like screwdriver... ok. But allen keys?
When I was leaving the island a couple of weeks ago the inspector found my Leatherman in the bottom of my camera bag; I know the rules and I have no recollection of putting it in there. I gave that Leatherman to my dad in 1990 or so, and I got it back when he died; I did not want to lose it, so I figured it was worth a try to take it back to the ticket counter to see if I could get it into one of my checked bags. Of course, my bags were already gone, but there was a guy at the counter who was on the same plane as me. When he saw what was going on he graciously offered to put my Leatherman into his checked bag; he found me at the baggage carousel in Houston and returned it to me. Whatta guy!