The Contractor agrees to fully indemnify and save whole and harmless the County of Tarrant from all costs or damages arising out of any real or. A letter agreement is a written legal document that is made between two parties who want a simple way to make their discussions of a transaction official.Drafting an agreement letter can help you document negotiations or establish working relations between two or more parties. The letter should include as much information as possible about the project or employment offer. Customize any template in minutes with PandaDoc.