You need to read the sage advice. Being able to “see your target” means “must have a line of sight”. Full cover, such as a glass window, or a wall of force, block line of sight, so, as far as spells are concerned, you cannot “see” through them. For the same reason you cannot normally use a mirror reflection or remote viewing device to target your spells. Since misty step requires you to be able to be able to “see” your destination, you cannot use it to pass through a glass window, never mind a wall of force. Dimension Door works fine though since you don’t need to be able to see your destination.