Gets the descriptions of a parameter from different commands in one or more modules.

Get-ParameterDescription.ps1

<#
    .SYNOPSIS
    Gets the descriptions of a parameter from different
    cmdlets in one or more modules. 
            
    .DESCRIPTION
    The Get-ParameterDescriptionfromXMLFile script returns the
    description of a parameter from cmdlets in one/more modules. 
    If the cmdlet has the parameter, but the description is blank,
    the script returns the blank description.

    .PARAMETER ParameterName
    Specifies the name of the parameter. The script returns the
    descriptions of this parameter from the topics of cmdlets 
    that have the parameter. The blank descriptions indicate that
    the cmdlet help topic has the parameter, but the description
    is blank.

    .PARAMETER  ModuleName
    Searches for the parameter only in the specified module. By
    default, this script searches all modules in the session.

    .EXAMPLE
    .\Get-ParameterDescriptionfromXMLfile.ps1 -ParameterName Slot

    Get-AzureDeployment                           Specifies the environment for the deployment. Choices are Staging or Production. If not specified...
    Get-AzureRole                                 Specifies the Azure deployment environment. Choices are "Production" or "Staging".                  
    Get-AzureServiceADDomainExtension             
    Get-AzureServiceAntimalwareConfig             
    Get-AzureServiceDiagnosticsExtension          Specifies the environment of the deployment to modify. Supported values are "Production" or "Stag...
    Get-AzureServiceExtension                     
    Get-AzureServiceRemoteDesktopExtension        Specifies the environment of the deployment to get. Supported values are "Production" or "Staging". 
    ...

    .EXAMPLE
    .\Get-ParameterDescriptionfromXMLfile.ps1 -ParameterName Slot -Module Azure

    .NOTES
    For help with this script, see JuneB, x65065
#>

Param
      (
         [parameter(Mandatory=$True)]
         [String]
         $ParameterName,

         [parameter(Mandatory=$False)]
         [String]
         $ModuleName
       )


if ($ModuleName) {$cmdlets = Get-Command -ParameterName $ParameterName -CommandType Cmdlet -Module $ModuleName}
else {$cmdlets = Get-Command -ParameterName $ParameterName -CommandType Cmdlet}

foreach ($cmdlet in $cmdlets)
{
    $cmdletName = $cmdlet.Name
    $parm = Get-Help $cmdletName -Parameter $ParameterName -ErrorAction SilentlyContinue
        
    if ($ModuleName)
    {
        [PSCustomObject]@{"Cmdlet"=$cmdletName; "Description"=$parm.description.text}
    }
    else
    {
        [PSCustomObject]@{"Cmdlet"=$cmdletName; "Module"=$cmdlet.ModuleName; "Description"=$parm.description.text}    
    }
}