Add back description updates to grouplifecyclepolicy-addgroup.md

Author: FaithOmbongi

api-reference/v1.0/api/grouplifecyclepolicy-addgroup.md

@@ -1,6 +1,6 @@
 ---
 title: "groupLifecyclePolicy: addGroup"
-description: "Adds a group to a lifecycle policy."
+description: "Add a group to a groupLifecyclePolicy."
 author: "yuhko-msft"
 ms.reviewer: "mbhargav, khotzteam, aadgroupssg"
 ms.localizationpriority: medium
@@ -13,7 +13,7 @@ ms.date: 04/04/2024
 
 Namespace: microsoft.graph
 
-Adds specific groups to a lifecycle policy. This action limits the group lifecycle policy to a set of groups only if the **managedGroupTypes** property of [groupLifecyclePolicy](../resources/grouplifecyclepolicy.md) is set to `Selected`.
+Add a group to a [groupLifecyclePolicy](../resources/grouplifecyclepolicy.md). This action is supported only if the **managedGroupTypes** property of the policy is set to `Selected`.
 
 [!INCLUDE [national-cloud-support](../../includes/all-clouds.md)]
 
@@ -53,7 +53,7 @@ Only one group can be added per request.
 
 ## Response
 
-If successful, this method returns `200 OK` response code. If the group is added to the policy, a `true` value is returned in the response body. Otherwise, a `false` value is returned in the response body.
+If successful, this method returns `200 OK` response code. If the group is added to the policy, a `true` value is returned in the response body and the **expirationDateTime** property of the added group is set based on the policy's **groupLifetimeInDays** value. Otherwise, a `false` value is returned in the response body.
 
 ## Example