Sometime when you have a XML schema it is difficult to get started with how you XML document should look. This is where the Create Sample XML Document tool helps you.
E.g. When your XML Schema (XSD) has a target namespace set you may be unaware that your XML document must use the target namespace. This could lead to hours of frustration as the validation tells you the seemingly good XML document is invalid against your schema.
However, if you run the Create Sample XML Document tool, the sample XML document generated for you will have the correct namespaces declared giving you a head start.
See also Liquid XML product documentation Create Sample XML Document.