diff --git a/tempest/api/volume/admin/test_backends_capabilities.py b/tempest/api/volume/admin/test_backends_capabilities.py
index 1351704..3c76eca 100644
--- a/tempest/api/volume/admin/test_backends_capabilities.py
+++ b/tempest/api/volume/admin/test_backends_capabilities.py
@@ -20,6 +20,7 @@
 
 
 class BackendsCapabilitiesAdminTestsJSON(base.BaseVolumeAdminTest):
+    """Test backends capabilities"""
 
     @classmethod
     def resource_setup(cls):
@@ -32,14 +33,16 @@
 
     @decorators.idempotent_id('3750af44-5ea2-4cd4-bc3e-56e7e6caf854')
     def test_get_capabilities_backend(self):
-        # Test backend properties
+        """Test getting backend capabilities"""
         # Check response schema
         self.admin_capabilities_client.show_backend_capabilities(self.hosts[0])
 
     @decorators.idempotent_id('a9035743-d46a-47c5-9cb7-3c80ea16dea0')
     def test_compare_volume_stats_values(self):
-        # Test values comparison between show_backend_capabilities
-        # to show_pools
+        """Test comparing volume stats values
+
+        Compare volume stats between show_backend_capabilities and show_pools.
+        """
         VOLUME_STATS = ('vendor_name',
                         'volume_backend_name',
                         'storage_protocol')
diff --git a/tempest/api/volume/admin/test_group_snapshots.py b/tempest/api/volume/admin/test_group_snapshots.py
index c57766e..0a8b56d 100644
--- a/tempest/api/volume/admin/test_group_snapshots.py
+++ b/tempest/api/volume/admin/test_group_snapshots.py
@@ -62,12 +62,26 @@
 
 
 class GroupSnapshotsTest(BaseGroupSnapshotsTest):
+    """Test group snapshot"""
+
     _api_version = 3
     min_microversion = '3.14'
     max_microversion = 'latest'
 
     @decorators.idempotent_id('1298e537-f1f0-47a3-a1dd-8adec8168897')
     def test_group_snapshot_create_show_list_delete(self):
+        """Test create/show/list/delete group snapshot
+
+        1. Create volume type "volume_type1"
+        2. Create group type "group_type1"
+        3. Create group "group1" with "group_type1" and "volume_type1"
+        4. Create volume "volume1" with "volume_type1" and "group1"
+        5. Create group snapshot "group_snapshot1" with "group1"
+        6. Check snapshot created from "volume1" reaches available status
+        7. Check the created group snapshot "group_snapshot1" is in the list
+           of all group snapshots
+        8. Delete group snapshot "group_snapshot1"
+        """
         # Create volume type
         volume_type = self.create_volume_type()
 
@@ -118,6 +132,18 @@
 
     @decorators.idempotent_id('eff52c70-efc7-45ed-b47a-4ad675d09b81')
     def test_create_group_from_group_snapshot(self):
+        """Test creating group from group snapshot
+
+        1. Create volume type "volume_type1"
+        2. Create group type "group_type1"
+        3. Create group "group1" with "group_type1" and "volume_type1"
+        4. Create volume "volume1" with "volume_type1" and "group1"
+        5. Create group snapshot "group_snapshot1" with "group1"
+        6. Check snapshot created from "volume1" reaches available status
+        7. Create group "group2" from "group_snapshot1"
+        8. Check the volumes belonging to "group2" reach available status
+        9. Check "group2" reaches available status
+        """
         # Create volume type
         volume_type = self.create_volume_type()
 
@@ -161,6 +187,20 @@
     @decorators.idempotent_id('7d7fc000-0b4c-4376-a372-544116d2e127')
     @decorators.related_bug('1739031')
     def test_delete_group_snapshots_following_updated_volumes(self):
+        """Test deleting group snapshot following updated volumes
+
+        1. Create volume type "volume_type1"
+        2. Create group type "group_type1"
+        3. Create group "group1" with "group_type1" and "volume_type1"
+        4. Create 2 volumes "volume1" and "volume2"
+           with "volume_type1" and "group1"
+        5. For each created volume, removing and then adding back to "group1"
+        6. Create group snapshot "group_snapshot1" with "group1"
+        7. Check snapshots created from "volume1" and "volume2" reach
+           available status
+        8. Delete "group_snapshot1"
+        9. Check snapshots created from "volume1" and "volume2" are deleted
+        """
         volume_type = self.create_volume_type()
 
         group_type = self.create_group_type()
@@ -211,6 +251,8 @@
 
 
 class GroupSnapshotsV319Test(BaseGroupSnapshotsTest):
+    """Test group snapshot with volume microversion greater than 3.18"""
+
     _api_version = 3
     min_microversion = '3.19'
     max_microversion = 'latest'
@@ -218,6 +260,7 @@
     @decorators.idempotent_id('3b42c9b9-c984-4444-816e-ca2e1ed30b40')
     @decorators.skip_because(bug='1770179')
     def test_reset_group_snapshot_status(self):
+        """Test resetting group snapshot status to creating/available/error"""
         # Create volume type
         volume_type = self.create_volume_type()
 
diff --git a/tempest/api/volume/admin/test_group_type_specs.py b/tempest/api/volume/admin/test_group_type_specs.py
index c5e6d1a..159c6fb 100644
--- a/tempest/api/volume/admin/test_group_type_specs.py
+++ b/tempest/api/volume/admin/test_group_type_specs.py
@@ -19,12 +19,15 @@
 
 
 class GroupTypeSpecsTest(base.BaseVolumeAdminTest):
+    """Test group type specs"""
+
     _api_version = 3
     min_microversion = '3.11'
     max_microversion = 'latest'
 
     @decorators.idempotent_id('bb4e30d0-de6e-4f4d-866c-dcc48d023b4e')
     def test_group_type_specs_create_show_update_list_delete(self):
+        """Test create/show/update/list/delete group type specs"""
         # Create new group type
         group_type = self.create_group_type()
 
diff --git a/tempest/api/volume/admin/test_group_types.py b/tempest/api/volume/admin/test_group_types.py
index 6723207..3993020 100644
--- a/tempest/api/volume/admin/test_group_types.py
+++ b/tempest/api/volume/admin/test_group_types.py
@@ -19,13 +19,15 @@
 
 
 class GroupTypesTest(base.BaseVolumeAdminTest):
+    """Test group types"""
+
     _api_version = 3
     min_microversion = '3.11'
     max_microversion = 'latest'
 
     @decorators.idempotent_id('dd71e5f9-393e-4d4f-90e9-fa1b8d278864')
     def test_group_type_create_list_update_show(self):
-        # Create/list/show group type.
+        """Test create/list/update/show group type"""
         name = data_utils.rand_name(self.__class__.__name__ + '-group-type')
         description = data_utils.rand_name("group-type-description")
         group_specs = {"consistent_group_snapshot_enabled": "<is> False"}
diff --git a/tempest/api/volume/admin/test_multi_backend.py b/tempest/api/volume/admin/test_multi_backend.py
index c5c70d2..a5de987 100644
--- a/tempest/api/volume/admin/test_multi_backend.py
+++ b/tempest/api/volume/admin/test_multi_backend.py
@@ -21,6 +21,7 @@
 
 
 class VolumeMultiBackendTest(base.BaseVolumeAdminTest):
+    """Test volume multi backends"""
 
     @classmethod
     def skip_checks(cls):
@@ -78,24 +79,49 @@
 
     @decorators.idempotent_id('c1a41f3f-9dad-493e-9f09-3ff197d477cc')
     def test_backend_name_reporting(self):
-        # get volume id which created by type without prefix
+        """Test backend name reporting for volume when type is without prefix
+
+        1. Create volume type, with 'volume_backend_name' as extra spec key
+        2. Create volume using the created volume type
+        3. Check 'os-vol-host-attr:host' of the volume info, the value should
+           contain '@' character, like 'cinder@CloveStorage#tecs_backend'
+        """
         for volume_id in self.volume_id_list_without_prefix:
             self._test_backend_name_reporting_by_volume_id(volume_id)
 
     @decorators.idempotent_id('f38e647f-ab42-4a31-a2e7-ca86a6485215')
     def test_backend_name_reporting_with_prefix(self):
-        # get volume id which created by type with prefix
+        """Test backend name reporting for volume when type is with prefix
+
+        1. Create volume type, with 'capabilities:volume_backend_name' as
+           extra spec key
+        2. Create volume using the created volume type
+        3. Check 'os-vol-host-attr:host' of the volume info, the value should
+           contain '@' character, like 'cinder@CloveStorage#tecs_backend'
+        """
         for volume_id in self.volume_id_list_with_prefix:
             self._test_backend_name_reporting_by_volume_id(volume_id)
 
     @decorators.idempotent_id('46435ab1-a0af-4401-8373-f14e66b0dd58')
     def test_backend_name_distinction(self):
-        # get volume ids which created by type without prefix
+        """Test volume backend distinction when type is without prefix
+
+        1. For each backend, create volume type with 'volume_backend_name'
+           as extra spec key
+        2. Create volumes using the created volume types
+        3. Check 'os-vol-host-attr:host' of each created volume is different.
+        """
         self._test_backend_name_distinction(self.volume_id_list_without_prefix)
 
     @decorators.idempotent_id('4236305b-b65a-4bfc-a9d2-69cb5b2bf2ed')
     def test_backend_name_distinction_with_prefix(self):
-        # get volume ids which created by type without prefix
+        """Test volume backend distinction when type is with prefix
+
+        1. For each backend, create volume type with
+           'capabilities:volume_backend_name' as extra spec key
+        2. Create volumes using the created volume types
+        3. Check 'os-vol-host-attr:host' of each created volume is different.
+        """
         self._test_backend_name_distinction(self.volume_id_list_with_prefix)
 
     def _get_volume_host(self, volume_id):
diff --git a/tempest/api/volume/admin/test_snapshots_actions.py b/tempest/api/volume/admin/test_snapshots_actions.py
index 41849bc..4fca240 100644
--- a/tempest/api/volume/admin/test_snapshots_actions.py
+++ b/tempest/api/volume/admin/test_snapshots_actions.py
@@ -22,6 +22,8 @@
 
 
 class SnapshotsActionsTest(base.BaseVolumeAdminTest):
+    """Test volume snapshot actions"""
+
     @classmethod
     def skip_checks(cls):
         super(SnapshotsActionsTest, cls).skip_checks()
@@ -65,7 +67,7 @@
 
     @decorators.idempotent_id('3e13ca2f-48ea-49f3-ae1a-488e9180d535')
     def test_reset_snapshot_status(self):
-        # Reset snapshot status to creating
+        """Test resetting snapshot status to creating"""
         status = 'creating'
         self.admin_snapshots_client.reset_snapshot_status(
             self.snapshot['id'], status)
@@ -74,6 +76,10 @@
 
     @decorators.idempotent_id('41288afd-d463-485e-8f6e-4eea159413eb')
     def test_update_snapshot_status(self):
+        """Test updating snapshot
+
+        Update snapshot status to 'error' and progress to '80%'.
+        """
         # Reset snapshot status to creating
         status = 'creating'
         self.admin_snapshots_client.reset_snapshot_status(
@@ -95,20 +101,20 @@
 
     @decorators.idempotent_id('05f711b6-e629-4895-8103-7ca069f2073a')
     def test_snapshot_force_delete_when_snapshot_is_creating(self):
-        # test force delete when status of snapshot is creating
+        """Test force delete when status of snapshot is creating"""
         self._create_reset_and_force_delete_temp_snapshot('creating')
 
     @decorators.idempotent_id('92ce8597-b992-43a1-8868-6316b22a969e')
     def test_snapshot_force_delete_when_snapshot_is_deleting(self):
-        # test force delete when status of snapshot is deleting
+        """Test force delete when status of snapshot is deleting"""
         self._create_reset_and_force_delete_temp_snapshot('deleting')
 
     @decorators.idempotent_id('645a4a67-a1eb-4e8e-a547-600abac1525d')
     def test_snapshot_force_delete_when_snapshot_is_error(self):
-        # test force delete when status of snapshot is error
+        """Test force delete when status of snapshot is error"""
         self._create_reset_and_force_delete_temp_snapshot('error')
 
     @decorators.idempotent_id('bf89080f-8129-465e-9327-b2f922666ba5')
     def test_snapshot_force_delete_when_snapshot_is_error_deleting(self):
-        # test force delete when status of snapshot is error_deleting
+        """Test force delete when status of snapshot is error_deleting"""
         self._create_reset_and_force_delete_temp_snapshot('error_deleting')
diff --git a/tempest/api/volume/admin/test_volume_quota_classes.py b/tempest/api/volume/admin/test_volume_quota_classes.py
index ee52354..f482788 100644
--- a/tempest/api/volume/admin/test_volume_quota_classes.py
+++ b/tempest/api/volume/admin/test_volume_quota_classes.py
@@ -30,6 +30,7 @@
 
 
 class VolumeQuotaClassesTest(base.BaseVolumeAdminTest):
+    """Test volume quota classes"""
 
     def setUp(self):
         # Note(jeremy.zhang): All test cases in this class need to externally
@@ -44,6 +45,7 @@
 
     @decorators.idempotent_id('abb9198e-67d0-4b09-859f-4f4a1418f176')
     def test_show_default_quota(self):
+        """Test showing default volume quota class set"""
         # response body is validated by schema
         default_quotas = self.admin_quota_classes_client.show_quota_class_set(
             'default')['quota_class_set']
@@ -51,6 +53,11 @@
 
     @decorators.idempotent_id('a7644c63-2669-467a-b00e-452dd5c5397b')
     def test_update_default_quota(self):
+        """Test updating default volume quota class set
+
+        Check current project and new project's default quota are updated
+        to the provided one.
+        """
         LOG.debug("Get the current default quota class values")
         body = self.admin_quota_classes_client.show_quota_class_set(
             'default')['quota_class_set']
diff --git a/tempest/api/volume/admin/test_volume_types.py b/tempest/api/volume/admin/test_volume_types.py
index ecc850e..ebcd3b7 100644
--- a/tempest/api/volume/admin/test_volume_types.py
+++ b/tempest/api/volume/admin/test_volume_types.py
@@ -23,17 +23,18 @@
 
 
 class VolumeTypesTest(base.BaseVolumeAdminTest):
+    """Test volume types"""
 
     @decorators.idempotent_id('9d9b28e3-1b2e-4483-a2cc-24aa0ea1de54')
     def test_volume_type_list(self):
-        # List volume types.
+        """Test listing volume types"""
         body = \
             self.admin_volume_types_client.list_volume_types()['volume_types']
         self.assertIsInstance(body, list)
 
     @decorators.idempotent_id('c03cc62c-f4e9-4623-91ec-64ce2f9c1260')
     def test_volume_crud_with_volume_type_and_extra_specs(self):
-        # Create/update/get/delete volume with volume_type and extra spec.
+        """Test create/update/get/delete volume with volume_type"""
         volume_types = list()
         vol_name = data_utils.rand_name(self.__class__.__name__ + '-volume')
         proto = CONF.volume.storage_protocol
@@ -80,7 +81,7 @@
 
     @decorators.idempotent_id('4e955c3b-49db-4515-9590-0c99f8e471ad')
     def test_volume_type_create_get_delete(self):
-        # Create/get volume type.
+        """Test create/get/delete volume type"""
         name = data_utils.rand_name(self.__class__.__name__ + '-volume-type')
         description = data_utils.rand_name("volume-type-description")
         proto = CONF.volume.storage_protocol
@@ -118,7 +119,7 @@
 
     @decorators.idempotent_id('7830abd0-ff99-4793-a265-405684a54d46')
     def test_volume_type_encryption_create_get_update_delete(self):
-        # Create/get/update/delete encryption type.
+        """Test create/get/update/delete volume encryption type"""
         create_kwargs = {'provider': 'LuksEncryptor',
                          'control_location': 'front-end'}
         volume_type_id = self.create_volume_type()['id']
@@ -175,6 +176,7 @@
 
     @decorators.idempotent_id('cf9f07c6-db9e-4462-a243-5933ad65e9c8')
     def test_volume_type_update(self):
+        """Test updating volume type details"""
         # Create volume type
         volume_type = self.create_volume_type()
 
diff --git a/tempest/api/volume/admin/test_volume_types_extra_specs_negative.py b/tempest/api/volume/admin/test_volume_types_extra_specs_negative.py
index fe249d6..6b2a278 100644
--- a/tempest/api/volume/admin/test_volume_types_extra_specs_negative.py
+++ b/tempest/api/volume/admin/test_volume_types_extra_specs_negative.py
@@ -20,6 +20,7 @@
 
 
 class ExtraSpecsNegativeTest(base.BaseVolumeAdminTest):
+    """Negative tests of volume type extra specs"""
 
     @classmethod
     def resource_setup(cls):
@@ -30,7 +31,7 @@
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('08961d20-5cbb-4910-ac0f-89ad6dbb2da1')
     def test_update_no_body(self):
-        # Should not update volume type extra specs with no body
+        """Test updating volume type extra specs with no body should fail"""
         self.assertRaises(
             lib_exc.BadRequest,
             self.admin_volume_types_client.update_volume_type_extra_specs,
@@ -39,7 +40,11 @@
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('25e5a0ee-89b3-4c53-8310-236f76c75365')
     def test_update_nonexistent_extra_spec_id(self):
-        # Should not update volume type extra specs with nonexistent id.
+        """Test updating volume type extra specs with non existent name
+
+        Updating volume type extra specs with non existent extra spec name
+        should fail.
+        """
         extra_spec = {"spec1": "val2"}
         self.assertRaises(
             lib_exc.BadRequest,
@@ -50,7 +55,10 @@
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('9bf7a657-b011-4aec-866d-81c496fbe5c8')
     def test_update_none_extra_spec_id(self):
-        # Should not update volume type extra specs with none id.
+        """Test updating volume type extra specs without name
+
+        Updating volume type extra specs without extra spec name should fail.
+        """
         extra_spec = {"spec1": "val2"}
         self.assertRaises(
             lib_exc.BadRequest,
@@ -60,8 +68,7 @@
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('a77dfda2-9100-448e-9076-ed1711f4bdfc')
     def test_update_multiple_extra_spec(self):
-        # Should not update volume type extra specs with multiple specs as
-        # body.
+        """Test updating multiple volume type extra specs should fail"""
         extra_spec = {"spec1": "val2", "spec2": "val1"}
         self.assertRaises(
             lib_exc.BadRequest,
@@ -72,8 +79,11 @@
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('49d5472c-a53d-4eab-a4d3-450c4db1c545')
     def test_create_nonexistent_type_id(self):
-        # Should not create volume type extra spec for nonexistent volume
-        # type id.
+        """Test creating volume type extra specs for non existent volume type
+
+        Creating volume type extra specs for non existent volume type should
+        fail.
+        """
         extra_specs = {"spec2": "val1"}
         self.assertRaises(
             lib_exc.NotFound,
@@ -83,7 +93,10 @@
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('c821bdc8-43a4-4bf4-86c8-82f3858d5f7d')
     def test_create_none_body(self):
-        # Should not create volume type extra spec for none POST body.
+        """Test creating volume type extra spec with none POST body
+
+        Creating volume type extra spec with none POST body should fail.
+        """
         self.assertRaises(
             lib_exc.BadRequest,
             self.admin_volume_types_client.create_volume_type_extra_specs,
@@ -92,7 +105,10 @@
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('bc772c71-1ed4-4716-b945-8b5ed0f15e87')
     def test_create_invalid_body(self):
-        # Should not create volume type extra spec for invalid POST body.
+        """Test creating volume type extra spec with invalid POST body
+
+        Creating volume type extra spec with invalid POST body should fail.
+        """
         self.assertRaises(
             lib_exc.BadRequest,
             self.admin_volume_types_client.create_volume_type_extra_specs,
@@ -101,8 +117,11 @@
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('031cda8b-7d23-4246-8bf6-bbe73fd67074')
     def test_delete_nonexistent_volume_type_id(self):
-        # Should not delete volume type extra spec for nonexistent
-        # type id.
+        """Test deleting volume type extra spec for non existent volume type
+
+        Deleting volume type extra spec for non existent volume type should
+        fail.
+        """
         self.assertRaises(
             lib_exc.NotFound,
             self.admin_volume_types_client.delete_volume_type_extra_specs,
@@ -111,7 +130,11 @@
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('dee5cf0c-cdd6-4353-b70c-e847050d71fb')
     def test_list_nonexistent_volume_type_id(self):
-        # Should not list volume type extra spec for nonexistent type id.
+        """Test listing volume type extra spec for non existent volume type
+
+        Listing volume type extra spec for non existent volume type should
+        fail.
+        """
         self.assertRaises(
             lib_exc.NotFound,
             self.admin_volume_types_client.list_volume_types_extra_specs,
@@ -120,7 +143,11 @@
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('9f402cbd-1838-4eb4-9554-126a6b1908c9')
     def test_get_nonexistent_volume_type_id(self):
-        # Should not get volume type extra spec for nonexistent type id.
+        """Test getting volume type extra spec for non existent volume type
+
+        Getting volume type extra spec for non existent volume type should
+        fail.
+        """
         self.assertRaises(
             lib_exc.NotFound,
             self.admin_volume_types_client.show_volume_type_extra_specs,
@@ -129,8 +156,11 @@
     @decorators.attr(type=['negative'])
     @decorators.idempotent_id('c881797d-12ff-4f1a-b09d-9f6212159753')
     def test_get_nonexistent_extra_spec_name(self):
-        # Should not get volume type extra spec for nonexistent extra spec
-        # name.
+        """Test getting volume type extra spec for non existent spec name
+
+        Getting volume type extra spec for non existent extra spec name should
+        fail.
+        """
         self.assertRaises(
             lib_exc.NotFound,
             self.admin_volume_types_client.show_volume_type_extra_specs,
diff --git a/tempest/api/volume/admin/test_volumes_backup.py b/tempest/api/volume/admin/test_volumes_backup.py
index 45060d0..4edce99 100644
--- a/tempest/api/volume/admin/test_volumes_backup.py
+++ b/tempest/api/volume/admin/test_volumes_backup.py
@@ -26,6 +26,7 @@
 
 
 class VolumesBackupsAdminTest(base.BaseVolumeAdminTest):
+    """Test volume backups"""
 
     @classmethod
     def skip_checks(cls):
@@ -122,6 +123,7 @@
 
     @decorators.idempotent_id('47a35425-a891-4e13-961c-c45deea21e94')
     def test_volume_backup_reset_status(self):
+        """Test resetting volume backup status to error"""
         # Create a volume
         volume = self.create_volume()
         # Create a backup