Before Crysis 2 had came out, I promised myself I would get every achievement. I spent countless hours grinding for them, and eventually I only lacked two achievements. One of which I still don't have, the other was "Tooled Up." Now, I was level 50 and had all guns...yet the achievement hadn't popped. I searched all over the internet, and from what I read the best fixes are as follows: 1) Reboot the nanosuit and play a few games. Many people reported that the achievement popped after this. 2) Use the tokens on guns in the order you unlock them. See, the Jackal was the last weapon I spent a token on, and I believe this was the reason for it not working. For ex: don't unlock C4 (one of the later weapons) before a Mk.60.

Now you may know how to avoid it, but you may not want to reboot. Well, this worked for me...but I'm unsure if it will work for others. Two days ago I got my hands on the limited edition code (you can buy them for about five bucks on eBay) and redeemed it at the main menu of Crysis 2. When I went to multiplayer after redeeming it, I noticed it took a while to load. Then voila! The achievement popped. For those looking for an answer it may not be in here, but I've done my best to provide one. Hope it works!