A good radiator hose on a vehicle should have a firm feeling to it and not be too hard or soft.
If the radiator hose feels too hard then it is likely going bad due to the rubber hose hardening overtime and also if the radiator hose feels spongy or bulges out then the radiator hoses are going bad and should be replaced before they burst.
When the engine is running and coolant is running through the radiator hoses they should firm up a bit and you can usually feel the coolant going through the radiator hoses.
Radiator hoses in poor or bad condition or are on the verge of failing feels spongy, soft, hard or even soft in one spot even if the rest of the hose feels firm.
When the radiator hose is not getting coolant through it then yes it can be a bit soft and you can sometimes squeeze the radiator hoses at least a little bit but they shouldn't be too soft.