Update tools at power cycle option is best option for tool upgrade. Find the below script which will enable this option in all VMs and also will give you the result in csv files.
First get connect with the Vcenter server on which you are going to perform this then list the VMs in VMname.txt if it is not for all VMs else use only Get-VM.
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#list name of servers on which changes required in file
$n = Get-Content "D:\Jitu\VMName.txt"
foreach ($b in $n){
#Command will extact details of VM
$vm = Get-VM -Name $b | % {Get-View $_.ID}
$value = New-Object VMware.Vim.VirtualMachineConfigSpec
$value.tools = New-Object VMware.Vim.ToolsConfigInfo
#This is where you mention which policy need to enter ,here we only need to enable checkbox to uprade vmware tools at power cycle. Same has been selected
$value.tools.toolsUpgradePolicy = "upgradeAtPowerCycle"
$vm.ReconfigVM_Task($value)
#Below command will export the policy details of all VMs(updated/yet to be updated) in respective VC in csv format.
get-view -ViewType virtualmachine | select name,@{N='ToolsUpgradePolicy';E={$_.Config.Tools.ToolsUpgradePolicy } } | Export-Csv "D:\ToolsOutput.csv" -UseCulture -NoTypeInformation
}
#or if we only need to export of tasks executed for number of VM then remove last line and add below instead of get-view:
$vm.ReconfigVM_Task($value)| Export-Csv "D:\ToolsOutput.csv" -UseCulture -NoTypeInformation
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