This document introduces assessment tools and their purpose in gathering evidence of competence. It defines assessment tools as the instruments and procedures used to assess competence, including specific questions or activities and instructions for candidates and assessors. Key principles for effective assessment tools are outlined, such as validity, reliability, flexibility and fairness. Guidelines are provided for developing assessment tools, including unpacking competency requirements, selecting methods, developing instructions, reviewing tools, and involving stakeholders. The importance of assessment tool design, review and version control to ensure quality assessment is emphasized.