When I was a mason contractor, I wore Lee white work pants. They were loose fitting and had pockets and lops all over them. For the most part, i always carried a brick hammer, folding rule, steel tape (usually 25 ft), several pointing tools, pencil, knife and a few other items, depending on the job.
When I was doing form or scaffolding constrution, I exchanged the brick hammer for a 20 oz carpenter hammer. At those times, i did need a nail bag. If I was climbing (scaffold construction, I wore a cloth bag with two pockets for the two sizes of duplex nails needed. For form work, i used a leather (fake leather) belt with the two pockets, again, two sizes of duplex nails.
Towards the end of my masonry days, kids, especially girls, started wearing those white pants with loops and pockets. the manufacturers recognized this and started making the real flimsy and they would not last thru more than a job or two before falling apart. I now need something only when working in my WW shop and for the most part, i wear an apron with lots of pockets and especially place for pencils and tape. a belt just gets in the way and i can hardly move around my MFT.
Tinker