I've used tool belts/nail bag's/pouche's etc quite a bit (when doing carpentery/fencing/decking's etc). They tend to esaily fill up with bits of rubbish they tend to let stuff fall out when (eg) your stooping over or bending or if they snag on something and the bag's lift up and let something fall out (usually something important like a nail bar or adjustable wrench) Plus they arent always comfortable to wear for long period's, thats why some types have added brace's to carry the weight. I would prefer to keep stuff in generous jacket or shirt pockets personally.