Added missing comment

Author: JonasKunz

javaagent-extension-api/src/main/java/io/opentelemetry/javaagent/extension/instrumentation/internal/ExperimentalInstrumentationModule.java

@@ -67,6 +67,10 @@ default List<String> agentPackagesToHide() {
    * method is invoked. This function allows to change the behaviour so that all Advice classes are
    * loaded and initialized as soon as a matching type is instrumented.
    *
+   * <p>Note: this functionality currently does not work together with the AdviceTransformer.
+   * Therefore you should make your Advices indy-compatible (use @Advice.AssignReturned) before
+   * using this feature.
+   *
    * @return true, if Advice classes should be loaded on instrumentation instead of first execution
    */
   default boolean loadAdviceClassesEagerly() {