First introduced in 2015, Contributor Role Ontologies and Taxonomies (CROTs) are the most recent innovation developed to address ethical issues of scholarly authorship. By providing a standard list of roles to specify individual contributions to publications, CROTs enhance transparency and consistency about the reporting of conducted tasks, and accordingly, improve the attribution of credit and responsibilities. Although various parties such as academic journals and universities are increasingly adopting CROTs, thus far no study has evaluated them from an ethical perspective. To fill this gap, this study develops an assessment instrument and subsequently analyses three major CROTs including CRediT, CRO and TaDiRAH, and provides recommendations for improving them from an ethical perspective. This study uses a bottom-up approach comprised of two literature reviews, combined with a review of non-conventional sources (i.e., forums, meeting notes, digital repositories) to collate concerns about authorship and use of CROTs, and generate candidate assessment criteria. Then with a top-down approach and using David Resnik’s 12 principles of research ethics, developed candidate assessment criteria are further analysed, and an assessment instrument consisting of 25 justified criteria is compiled. This instrument is used to identify the ethical strengths and weaknesses of CRediT, CRO and TaDiRAH. Finally, using current best practices and available technology in publication processes, recommendations are provided for further development and improvement of CROTs. Results show that CRediT satisfies more criteria than other CROTs. In relation to the attribution of credit and usability, CRediT provides unique options. However, unlike TaDiRAH that is translated into languages other than English, and CRO that has revised its roles, CRediT is only available in English and has not been updated yet. Improving CROTs benefits almost all parties involved in the development, production, or use of academic publications such as researchers, journal editors, librarians, hiring and promotion committees and funders.