Research has established the importance of teachers developing a meta-knowledge for talking about, teaching and assessing multimodal texts enhancing students’ intermodal awareness and digital literacy to navigate and interpret digital multimodal text designs. Existing models and frameworks recommend assessing meaning through modes beyond just language emphasizing the importance of explicit teaching of form, genre, and the use of a metalanguage. Based on the co-design work with teachers in the research project "Teachers' Meta-Knowledge and Assessment Practices in Digital, Multimodal Learning Environments" (2022-2024), this presentation aims to elaborate on tools for collaborative metathinking in teaching and assessing students’ digital multimodal meaning making.