diff --git a/nova/conf/availability_zone.py b/nova/conf/availability_zone.py
index c3f61639c2eb..4ad9017295c3 100644
--- a/nova/conf/availability_zone.py
+++ b/nova/conf/availability_zone.py
@@ -19,10 +19,48 @@ from oslo_config import cfg
 availability_zone_opts = [
     cfg.StrOpt('internal_service_availability_zone',
         default='internal',
-        help='The availability_zone to show internal services under'),
+        help="""
+This option specifies the name of the availability zone for the
+internal services. Services like nova-scheduler, nova-network,
+nova-conductor are internal services. These services will appear in
+their own internal availability_zone.
+
+Possible values:
+
+    * Any string representing an availability zone name
+    * 'internal' is the default value
+
+Services that use this:
+
+    * ``nova-api``
+
+Related options:
+
+    * None
+"""),
     cfg.StrOpt('default_availability_zone',
         default='nova',
-        help='Default compute node availability_zone'),
+        help="""
+Default compute node availability_zone.
+
+This option determines the availability zone to be used when it is not
+specified in the VM creation request. If this option is not set,
+the default availability zone 'nova' is used.
+
+Possible values:
+
+    * Any string representing an availability zone name
+    * 'nova' is the default value
+
+Services that use this:
+
+    * ``nova-api``
+    * ``nova-scheduler``
+
+Related options:
+
+    * None
+""")
 ]