By combining recommendations for effective assignment design with principles of transparency and the value-expectancy theory of achievement motivation, we developed a rubric capable of for assessing the quality and guiding the design of assignment descriptions. This rubric defines criteria characteristic of well-designed assignments; breaks the criteria down into concrete, measurable components; and suggests what evidence for each component might look like. While the full rubric is valid for major, signature assignments, it can accommodate a diverse range. It can also provide summative, quantitative information to educational developers for research and formative, qualitative feedback to instructors for gauging the quality of their assignments.