Awesome Reviewers

Use naming rules that keep identifiers consistent, unambiguous, and resilient to change:

Example (combining both practices):

private const string VmSubscriptionIdKey = "VM Subscription ID";

// ...
if (vmJob.ExtendedInfo.PropertyBag.ContainsKey(VmSubscriptionIdKey))
{
    detailedResponse.Properties.Add(
        VmSubscriptionIdKey,
        vmJob.ExtendedInfo.PropertyBag[VmSubscriptionIdKey]);
}

[Parameter(Mandatory = false, ValueFromPipelineByPropertyName = true)]
[Alias("Tag")]
public Hashtable Tag { get; set; }