The judge shall not accept a plea of guilty or nolo contendere without first determining, on the record, that the plea is voluntary. By inquiry of the prosecuting attorney and defense counsel, the judge should determine whether the tendered plea is the result of prior plea discussions and a plea agreement, and, if it is, what agreement has been reached. If the prosecuting attorney has agreed to seek charge or sentence leniency which must be approved by the judge, the judge must advise the defendant personally that the recommendations of the prosecuting attorney are not binding on the judge. The judge should then address the defendant personally and determine whether any other promises or any force or threats were used to obtain the plea.