I had a need to update description fields in many of my VMs and the vSphere client doesn’t exactly lend itself to being able to accomplish this quickly. I decided to use PowerCLI to dump a CSV of my VM names and description fields. I then updated the CSV and imported the new descriptions back into the VMs

First, to dump a CSV of VMs and descriptions in a particular cluster

Connect-VIServer "myserver.foo.com"
Get-Cluster "mycluster" | Get-VM | Select-object Name, Description | Export-CSV "myvms.csv"

Then, after updating the CSV with new description information, save the descriptions back into the VMs.

Connect-VIServer "myserver.foo.com"
$csv=Import-Csv "myvms.csv"
$csv | % { Set-VM $_.VMName -Description $_.Description -Confirm:$false }