Michelin makes a damn good tire probably one of the best. I would say just check them for small cracks ,and deterioration effects if ok ,should be fine.
Most tires have a wear Bar ,that is like a little bar molded into the tire that goes horizontal ,if you look close you can see them betweem treads.
If your tire has worn down to the wear bar ,they need to be replaced.That is if the tread and the wear bar are even depths ,you need new tires .
Take care .......Dean