identifying a particular illness using a combination of signs and symptoms

a diagnostic test 诊断性测试

Jaundice is diagnostic of liver failure. 黄疸可用于诊断肝衰竭。

used for making a judgment about what a particular problem is

The model is a useful diagnostic tool to determine what has the most impact on employees' performance. 该模式是一种有用的判断工具，用以识别对雇员工作最有影响的因素。