Add useful description in deploy

Change-Id: Iaa6baf658a2c8daa381494b12756ef99d6cbe472
diff --git a/jenkins/client/job/deploy/lab/mk/init.yml b/jenkins/client/job/deploy/lab/mk/init.yml
index bf58f39..d88f4d7 100644
--- a/jenkins/client/job/deploy/lab/mk/init.yml
+++ b/jenkins/client/job/deploy/lab/mk/init.yml
@@ -59,6 +59,7 @@
               HEAT_STACK_DELETE:
                 type: boolean
                 default: 'true'
+                description: "Don't enable it if you need to use the lab after"
               HEAT_STACK_REUSE:
                 type: boolean
                 default: 'false'