In the revised sentence, the status of the LLC as a managermanaged company is merely implied, not declared outright. An LLC agreement considers the formation of a "board" or "board of managers", how managers or managing members are selected, and who can appoint them.An LLC operating agreement can be as simple or as complex as you want it to be. At its core, an operating agreement is a legal instrument that defines the ownership of an LLC as well as how it works. An operating agreement is similar to a partnership agreement. It's a written agreement between members of a limited liability company (LLC). What is an Operating Agreement? Generally, an operating agreement replaces most of the rights and responsibilities outlined in the Act, with a few exceptions. A written operating agreement is a legal contract that is drawn up during business formation of a limited liability company (LLC).