This study aimed to compare 3 commonly used frailty assessment tools to examine their agreement and classification discrepancies, with the goal of informing more accurate frailty screening and personalized intervention planning in older adults. I analyzed data from the Korean Frailty and Aging Cohort Study (KFACS), a nationally representative dataset, including 3011 community-dwelling older adults aged 70 to 84 years. The CHS Frailty Index, Korean version of the FRAIL scale, and Korean Frailty Index were used. Participants' general health-related characteristics were also collected. Descriptive statistics and Pearson correlation analyses were conducted to evaluate the relationships between the tools. Missing data were excluded. All 3 tools successfully classified individuals as robust, pre-frail, or frail. The strongest correlation was observed between the CHS Frailty Index and the Korean FRAIL scale (r = .565), while the weakest correlation was found between the Korean FRAIL scale and Korean Frailty Index (r = .427). Although the tools showed significant associations, discrepancies in frailty classification across tools were identified. The findings suggest that while all 3 tools are appropriate for assessing frailty, differences in classification thresholds imply that tool selection should consider the health profile and the context in which screening occurs. The findings indicate that while all 3 tools are valid, differences in classification thresholds suggest that the choice of tool should depend on the screening context. Complementary use may enhance frailty identification and guide individualized care.