While large-scale language and writing assessments benefit from a wealth of literature on the reliability and validity of specific tests and rating procedures, there is comparatively less literature that explores the specific language of second language writing rubrics. This paper provides an analysis of the language of performance descriptors for the public versions of the TOEFL and IELTS writing assessment rubrics, with a focus on linguistic agency encoded by agentive verbs and language of ability encoded by modal verbs