Q. How can I check the versions of VM extensions that are available in Azure?

A. Using PowerShell it is easy to check on the version of agents. You need to know the publisher and image type. All available extensions and their version can be viewed with:

Get-AzureRmVmImagePublisher -Location EastUS | `
Get-AzureRmVMExtensionImageType | `
Get-AzureRmVMExtensionImage | Select Type, Version, PublisherName | ft -AutoSize

To view information for a specific agent enter the specific values, for example:

Get-AzureRmVMExtensionImage -Location EastUS -PublisherName Microsoft.EnterpriseCloud.Monitoring -Type MicrosoftMonitoringAgent | select *