This article describes key aspects of Essential 6 of the Second Edition of the National Association for Professional Development Schools (NAPDS) Nine Essentials--"Clearly Written Agreements." Clearly written agreements between parties serve as crucial components in ensuring the creation, effectiveness, success and sustainability of any partnership. Highlighted in Essential 6 of both the original and updated versions of the National Association for Professional Development Schools (NAPDS) guiding statement document, "What it Means to Be a Professional Development School" (NAPDS, 2008, 2021a), is the need for an articulated agreement to serve as a foundation of understanding among all parties involved. Essential 6, clearly communicated that an articulated agreement between partners is a critical attribute of a PDS, not just a document that comes into being as a result of naturally occurring interactions between/among partners. Essential 6 also emphasizes the inclusion of commitments and expectations to be clearly addressed in the articulated agreement documents instead of solely focusing on "roles and responsibilities of those involved." Essential 6 includes recommendations that specific processes are clearly outlined and partnerships must engage in the action of continuous improvement and renewal in response to lessons learned, changes needed and desires to strengthen aspects of the partnership.