An agreement that is otherwise sufficiently definite to be a contract is not invalid because it leaves particulars of performance to be specified by one of the parties. If particulars of performance are to be specified by a party, the following rules apply: Specification must be made in good faith and within limits set by commercial reasonableness. If a specification materially affects the other party’s performance but is not seasonably made, the other party: Is excused for any resulting delay in its performance; and May perform, suspend performance, or treat the failure to specify as a breach of contract.