diff --git a/sql/src/test/java/org/apache/druid/sql/calcite/DecoupledIgnore.java b/sql/src/test/java/org/apache/druid/sql/calcite/DecoupledIgnore.java
index d552c170b230..0838b596608a 100644
--- a/sql/src/test/java/org/apache/druid/sql/calcite/DecoupledIgnore.java
+++ b/sql/src/test/java/org/apache/druid/sql/calcite/DecoupledIgnore.java
@@ -69,7 +69,12 @@ Pattern getPattern()
     }
   };
 
-
+  /**
+   * Processes {@link DecoupledIgnore} annotations.
+   *
+   * Ensures that test cases disabled with that annotation can still not pass.
+   * If the error is as expected; the testcase is marked as "ignored".
+   */
   public static class DecoupledIgnoreProcessor implements TestRule
   {
     public Statement apply(Statement base, Description description)