The concept of smart city has been studied in a variety of forms and contexts. While previous studies highlight the extensive use of indicators of smartness, another stream of literature advocates the role of citizens in city transformations. In this viewpoint, we call for an extension of this dichotomous understanding and highlight the cross-sectoral collaborative nature of smart city; we also draw attention to the potential of smart city to generate multiple values for a range of stakeholders. We reflect on the Sustainable Development Goals (SDGs) agenda and Key Performance Indicators (KPIs) for sustainable and smart cities developed by the United Nations (UN) as a possible measurement tool for these multiple values. Based on an analysis of the literature on smart cities and an overview of the UN documents, including a short illustration of the case of Moscow (Russia), we articulate concerns regarding the ability of these global tools to grasp the complex nature of smart city, as well as the contextual specifics of each case locally.