What is the test for determining whether a contract is ambiguous or ambiguous?

Under New York law, "if a contract is straightforward and unambiguous, its interpretation presents a question of law for the court to be made without resort to extrinsic evidence." Postlewaite v. McGraw-Hill, Inc. , 411 F.3d 63, 67 (2d Cir. 2005) (internal quotation marks omitted). But if "the intent of the parties can[not] be ascertained from the face of their agreement," the contract is ambiguous and its interpretation presents a question of fact. Id. (internal quotation marks omitted).