With the advent of online learning, instructors are challenged to engage with students in asynchronous learning environments. This study explored Perusall, a social annotation tool (SAT), in an undergraduate introductory course in sign language interpreting. Despite the growing popularity of SATs, their impact on sign language interpreter education still needs to be explored. This project utilised a qualitative case study approach and involved 11 undergraduate students enrolled in an 8-week asynchronous course. Data were collected through Perusall analytics, student annotations, and post-course surveys. Findings indicated that students had a positive experience with Perusall, especially its ability to facilitate interaction and deepen understanding of course materials. The tool supported a social constructivist learning approach by promoting collaborative learning and peer-to-peer interaction. Another key finding was that Perusall increased reading time and completion rates. A qualitative analysis of the students' annotations identified significant themes regarding their perceived subjectivity as student interpreters, such as self-esteem, advocacy, and allyship. Overall, using Perusall proved beneficial, fostering a sense of community and enhancing students' engagement and understanding of the material. It also provided insights into the students' experiences that may not have been present in a traditional discussion board or face-to-face class conversation.