A more thorough explanation:

Definition: Descriptive refers to a statement that describes reality. It is a theory that claims to explain how things really are, rather than how they should be. It is the opposite of prescriptive.

• "The sky is blue" is a descriptive statement because it describes the color of the sky as it is in reality.
• "The grass is green" is another example of a descriptive statement because it describes the color of the grass as it is in reality.

These examples illustrate the definition of descriptive because they are statements that describe the reality of the color of the sky and grass. They do not prescribe or suggest what color the sky or grass should be, but rather describe what they are in reality.