One of the following is a formal document that provides an overview of the security requirements for the information system, describes the system and the security controls in place or planned for…

An Initial Risk Assessment identifies potential risks early on but does not provide a comprehensive description of the system or its implemented security controls.

A Security Plan (SP) is a formal document that details an information system, its boundaries, its security requirements, and the specific security controls that are implemented or planned to meet those requirements. It is a foundational document in the system authorization process.

Security and Privacy Assessment Reports document the results of control assessments, providing evidence of control effectiveness, but they are not the primary document describing the system and its controls.

A Plan of Action and Milestones (POA&M) is used to track the remediation of identified security weaknesses, not to initially describe the system and its security controls.