HDDS-2816. Fix shell description for --start parameter of listing keys (#601)

diff --git a/hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/web/ozShell/keys/ListKeyHandler.java b/hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/web/ozShell/keys/ListKeyHandler.java
index 71443d2..8d699d1 100644
--- a/hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/web/ozShell/keys/ListKeyHandler.java
+++ b/hadoop-ozone/ozone-manager/src/main/java/org/apache/hadoop/ozone/web/ozShell/keys/ListKeyHandler.java
@@ -50,7 +50,8 @@
   private int maxKeys;
 
   @Option(names = {"--start", "-s"},
-      description = "The first key to start the listing")
+      description = "The key to start the listing from.\n" +
+              "This will be excluded from the result.")
   private String startKey;
 
   @Option(names = {"--prefix", "-p"},