No Tools!

Hi guys,
I just got Garry’s Mod as a gift from a friend. I play it on a Mac, and when I download it, I noticed that when I press q in-game and try to access the tools tabs, it is empty inside! There are NO TOOLS whatsoever. Can someone tell me how to fix this please?! I kinda need the welding tool etc y’know.
I did run the thing on steam which said: verify integrity of game cache. Maybe that was the problem? Please help!

Ultimate fix: Get a PC!

W00T! Yeah no kidding. I will be getting one very soon. Hate my mac. And I was actually able to fix this problem on my own.