The current interest in formative assessment practices has led to a permanent innovation of formative assessment tasks. Although the process of rigorously designing and applying assessment tasks is crucial for the success of the formative assessment process, not much attention has been paid to the quality of tasks used within formative assessment practices. One way to judge the quality of assessment tasks is to analyze their authenticity features: realism, complexity, challenge, collaboration, reflection, and diversity. This article uses a narrative review method, retrieving articles from three scientific databases to analyze if tasks reported in formative assessment research practices are authentic. Also, it aims to describe, based on the tasks revised, the best practices to approach each of the authenticity criteria. Furthermore, this paper discusses how the structure of the tasks used (objective or subjective) influences authenticity features. Results indicate that in general, tasks need to be more complex, collaborative, reflective and diversified.