To refer the overload definitions/syntax of a method of an object using the OverloadDefinitions property of a method with simple dot notation, or simply use the method name without the parenthesis ()
.
<object>.<method>.OverloadDefinitions
# or
<object>.<method>
$Text = "PowerShell"
# To see all the methods of an object
$Text | Get-Member -MemberType *Method
$Text.LastIndexOf
# or
$Text.LastIndexOf.OverloadDefinitions