Add descriptions for SEO.

Author: TimShererWithAquent

articles/key-vault/key-vault-ovw-security-worlds.md

@@ -1,5 +1,6 @@
 ---
 title: Azure Key Vault security worlds | Microsoft Docs
+description: Azure Key Vault is a multi-tenant service. It uses a pool of HSMs in each Azure location. All locations in a geographic region share a cryptographic boundary.
 ms.service: key-vault
 ms.subservice: general
 ms.topic: conceptual

articles/key-vault/key-vault-ovw-soft-delete.md

@@ -1,5 +1,6 @@
 ---
 title: Azure Key Vault soft delete | Microsoft Docs
+description: Soft-delete in Azure Key Vault allows you to recover deleted key vaults and key vault objects, such as keys, secrets, and certificates.
 ms.service: key-vault
 ms.subservice: general
 ms.topic: conceptual

articles/key-vault/quick-create-powershell.md

@@ -1,6 +1,6 @@
 ---
 title: "Quickstart: Set & retrieve a secret from Key Vault using PowerShell"
-description: In this quickstart, learn how to create, retrieve, and delete secrets from an Azure key vault using PowerShell
+description: In this quickstart, learn how to create, retrieve, and delete secrets from an Azure Key Vault using Azure PowerShell.
 services: key-vault
 author: msmbaldwin
 manager: rkarlin
@@ -43,7 +43,7 @@ New-AzResourceGroup -Name ContosoResourceGroup -Location EastUS
 
 Next you create a Key Vault. When doing this step, you need some information:
 
-Although we use “Contoso KeyVault2” as the name for our Key Vault throughout this quickstart, you must use a unique name.
+Although we use "Contoso KeyVault2" as the name for our Key Vault throughout this quickstart, you must use a unique name.
 
 - **Vault name** Contoso-Vault2.
 - **Resource group name** ContosoResourceGroup.