I have a new belt in spare sitting in the boot along with all tools required for change. All my cars have this one item as carry spare along with tool roll.
I have checked the belt with a proper belt groove gauge and its perfect. Odd isnt it? The belt is pretty clean and the markings are not worn away. I can read the part no and date etc.
Originally I bought a new one to replace it - I took it out - checked it with a gauge (free from gates - available at spare parts shop) - the belt grooves are great - no chipping or cracking either. Its made by Continental.
Installed it back - just like the service manual says. Inspect belt and replace if required. - in this case the belt passed the test.
There is no vibration in the belt when the engine runs and the tensioner remains steady - changed the tensioner due to being a faulty design and had a slightly noisy roller.