I probably will need a new roof in the next few years. We bought our house 6 years ago with two layers already on it.
My criteria for contractors are pretty lax. Basic stuff, like showing up, doing the work such that it doesn't need correction, not creating a giant mess, not stealing from me, and either honoring their estimate or giving a justifiable reason for increasing the price ("my assistant didn't show so I have to hire someone else" doesn't count as justifiable).
In my experience, finding someone that can handle even half of those is next to impossible.