Incomplete contracts have always been viewed as raising the following challenge for contract law: does the incompleteness-or, "indefiniteness," as it is usually called-rise to such a level that renders the agreement legally unenforceable? When the indefiniteness concerns important terms, it is presumed that the parties have not reached an agreement to which they intend to be bound. This "fundamental policy" is the upshot of the view that "contracts should be made by the parties, not by the courts."' When, in contrast, the indefiniteness concerns less important terms, courts supplement the agreement with gap fillers and enforce the supplemented contract.
Ben-Shahar, Omri. "'Agreeing to Disagree': Filling Gaps in Deliberately Incomplete Contracts." Wis. L. Rev. 2004, no. 2 (2004): 389-428. (Freedom from Contract Symposium.)