The purpose for which a contract is made must be described as:

The purpose for which a contract is made must be described as legal because, for a contract to be enforceable, its object must not violate any laws or public policy. A contract that has an illegal purpose is void and therefore cannot be enforced by either party. This ensures that contracts promote lawful activities and do not contribute to illegal actions.

In contrast, concepts such as validity, mutual benefit, or being compelling do not accurately reflect this essential criterion. Validity refers more generally to whether the contract meets certain legal requirements, mutual benefit relates to the idea that both parties should gain something from the agreement, and compelling does not address the legality of the contract's purpose. Thus, the legal nature of the contract's purpose is what ultimately allows it to be upheld in a court.