The evolution of design to meet the growing sustainability challenges has led to the development of knowledge expressed in different approaches, principles and strategies. To be able to operationalize this knowledge, several design for sustainability (DfS) tools have been created. However, these tools have not been the target of massive and systematic practical use by designers, nor have they been the subject of many studies that allow analyzing, classifying and understanding their capabilities in a real context to improve application rates. With the end goal of supporting designers in using DfS tools more systematically, this research work aims to establish two essential foundations that can lay the ground for the practical selection and application of tools in the future: 1) a clear and comprehensive definition of what constitutes a DfS tool from the designer's perspective, including its scope and boundaries; 2) a list, hierarchization, and evaluation of criteria for classifying, organizing, and selecting tools based on project and designer needs. The methodology used in this research incorporates three main methods: 1) literature review to establish the state-of-the-art, basis for constructing a definition of DfS tool and for identifying and selecting criteria; 2) survey for designers to validate the main components of the DfS tool definition; 3) value analysis methodology for classifying and valuing the classification criteria by designers. Based on this process, it was possible to construct a comprehensive definition of what a DfS tool is and to establish and organize a set of criteria that can facilitate the classification and organization of tools. This allows for better identification of their characteristics, demands and functionalities to align the tools with the design process and its needs.