Learn what a letter of agreement is and how to write one, including a template and example to help you get started crafting your own. A Letter of Agreement is a document that outlines the terms and conditions of an agreement between two parties, like a more concise version of a contract.This Contract Specifications Manual provides terms and conditions which are applicable to all AGREEMENTS entered into between ALLEGHENY COUNTY DEPARTMENT OF. A. During and at the completion of the Residency Period, Sponsor agrees to: 1. Provide its professional services as administrator of the this program,. 2. Create a Letter of Agreement (LOA) using our free DIY printable template. Remind someone of their legal duties to you before initiating legal proceedings.