Radiator hoses when cold should be soft enough to squeeze easily with your hands.
If the radiator hoses are hard when they are cold then they are likely getting old and are about to eventually burst and leave you stranded.
If your radiator hoses are older than 10 years old and are hard you should replace them to prevent a potential breakdown.
When the radiator hoses are hot after the engine heats up the coolant then they should have some pressure on them which makes them hard to squeeze.
But you should still be able to squeeze the radiator hoses a little bit.
If the radiator hoses become too hard while the engine is at operating temperature then there could be too much coolant pressure built up which can be caused by cracked cylinder heads or a bad head gasket causing the cylinder pressure to get into the coolant system.