The paper deals with the issue of using the IMS Question and Test Interoperability standard for the development of assessment tools. This standard is based on XML (eXtensible Markup Language) and intended for description of tests at a structural level independent from the computer platform. According to this standard, questions and tests can be represented as plain text, which is marked-up with XML tags. The testing tool reads a test description in XML and parses it to translate into the format used internally in the system. This approach allows to create test descriptions that are highly interchangeable, readable, and reusable.