optimize kubectl version help info

Author: zhouya0

staging/src/k8s.io/kubectl/pkg/cmd/version/version.go

@@ -79,8 +79,8 @@ func NewCmdVersion(f cmdutil.Factory, ioStreams genericclioptions.IOStreams) *co
 			cmdutil.CheckErr(o.Run())
 		},
 	}
-	cmd.Flags().BoolVar(&o.ClientOnly, "client", o.ClientOnly, "Client version only (no server required).")
-	cmd.Flags().BoolVar(&o.Short, "short", o.Short, "Print just the version number.")
+	cmd.Flags().BoolVar(&o.ClientOnly, "client", o.ClientOnly, "If true, shows client version only (no server required).")
+	cmd.Flags().BoolVar(&o.Short, "short", o.Short, "If true, print just the version number.")
 	cmd.Flags().StringVarP(&o.Output, "output", "o", o.Output, "One of 'yaml' or 'json'.")
 	return cmd
 }