diff -r 8009cf5b833d -r a30edd277572 src/jdk.jpackage/share/classes/jdk/jpackage/internal/resources/MainResources.properties
--- a/src/jdk.jpackage/share/classes/jdk/jpackage/internal/resources/MainResources.properties	Mon Apr 15 12:03:26 2019 -0400
+++ b/src/jdk.jpackage/share/classes/jdk/jpackage/internal/resources/MainResources.properties	Thu Apr 18 19:36:55 2019 -0400
@@ -81,8 +81,8 @@
 ERR_MissingAppResources=Error: No application jars found.
 ERR_AppImageNotExist=Error: App image directory "{0}" does not exist.
 ERR_AppImageInvalid=Error: App image directory "{0}" does not contain "app" sub-directory.
-ERR_NoAddLauncherName=Error: Add Launchers require a name parameter.
-ERR_NoUniqueName=Error: Add Launchers require a unique name parameter.
+ERR_NoAddLauncherName=Error: --add-launcher option requires a name and a file path (--add-launcher <name>=<file path>).
+ERR_NoUniqueName=Error: --add-launcher <name>=<file path> requires a unique name.
 ERR_NoJreInstallerName=Error: Jre Installers require a name parameter.
 ERR_InvalidAppName=Error: Invalid Application name: {0}.
 ERR_InvalidSLName=Error: Invalid Add Launcher name: {0}.