The article discusses the development and refinement of the AGREE instrument, a tool used to assess the quality of clinical practice guidelines. Initially established by the AGREE Collaboration, the instrument was designed to evaluate the process and reporting of guideline development. Over time, issues such as non-compliance with methodologic standards and the need for more efficient evaluation processes emerged. The AGREE Next Steps Consortium addressed these issues through two studies, introducing a new seven-point response scale, evaluating the usefulness of items for different stakeholders, and enhancing the construct validity of the tool. The results led to the release of AGREE II, which includes 23 items grouped into six domains: scope and purpose, stakeholder involvement, rigour of development, clarity of presentation, applicability, and editorial independence. Key changes include a more explicit purpose, a seven-point response scale, and detailed user guidance. The consortium recommends AGREE II as the preferred instrument for guideline development, reporting, and evaluation, while acknowledging that it does not evaluate the clinical appropriateness or validity of recommendations. The article also highlights the instrument's applications and ongoing research initiatives.The article discusses the development and refinement of the AGREE instrument, a tool used to assess the quality of clinical practice guidelines. Initially established by the AGREE Collaboration, the instrument was designed to evaluate the process and reporting of guideline development. Over time, issues such as non-compliance with methodologic standards and the need for more efficient evaluation processes emerged. The AGREE Next Steps Consortium addressed these issues through two studies, introducing a new seven-point response scale, evaluating the usefulness of items for different stakeholders, and enhancing the construct validity of the tool. The results led to the release of AGREE II, which includes 23 items grouped into six domains: scope and purpose, stakeholder involvement, rigour of development, clarity of presentation, applicability, and editorial independence. Key changes include a more explicit purpose, a seven-point response scale, and detailed user guidance. The consortium recommends AGREE II as the preferred instrument for guideline development, reporting, and evaluation, while acknowledging that it does not evaluate the clinical appropriateness or validity of recommendations. The article also highlights the instrument's applications and ongoing research initiatives.