One day I was about to do a minor plumbing job at the house and tried to use it on the water valve next to the water meter (in a box in the ground). The valve would not move.
the water company i deal with most face-to-face frowns on using their side of the meter as a shut-off valve. their experience is, as mentioned in a previous post above, that the valve becomes frozen and can break when forced.
if that happens you've created a situation where you will have to call the water company to remedy. they will then need to shut off the water to the street - thereby affecting not only your water, but your neighbors. unpleasant at best.
the solution is to have a ball valve (not a gate valve) on your side of the meter - somewhere between the meter and the house. then you can operate it once a year or so to keep it free.
when i recently had a water company relocate their meter they installed - at no cost - a solid brass, industrial strength ball valve on my side of the meter that fit inside their concrete vault. they wanted to prevent future damage to their valve.
i don't think most water companies would do this w/o charge. but imho it's well worth the cost to have a plumber either change yours (a lot of homes have the gate valves) to a ball valve or install a new one in-line for you.
now you have no need for a tool that may wander.