As corporate attention to ESG issues continues to grow, the disagreement in ratings for the same company by different ESG rating agencies have sparked widespread discussion and concern. This report aims to explore how corporate efforts in ESG information disclosure can effectively reduce rating disagreements from the perspective of information asymmetry. Using a 2008–2022 sample of Chinese listed firms, we measure corporate ESG disclosure from annual reports and construct a metric of ESG rating divergence from ratings provided by domestic and international agencies. We examine the underlying mechanisms, including information asymmetry, analyst attention, and media oversight. We also investigate the sources of the change in ESG rating disagreement by examining whether the shift stems from domestic versus international agencies, or from incumbent versus new entrants. Besides, we examine how ESG disagreement affects corporate valuation (proxied by Tobin's Q) and how policy-driven changes in disclosure influence firm value, using a portfolio analysis approach. This report sheds light on the economic consequences of voluntary ESG information disclosure, providing support for the future establishment of unified ESG information disclosure standards.