That is also partially correct. Clouds reflect energy, they don't capture and release it. Both going outwards and coming inwards. As more energy is coming from the sun to earth than vice versa they're not bad per se.

You should also consider while vapour can act as an greenhouse gas, clouds (which are very small water droplets) are created from vapour as it condenses in the atmosphere and reflect the sun rays. They are thus doing the opposite of vapour. It is too cold in the upper atmosphere for the water to stay vapour for a longer time.