There are thousands of tests on the market. It’s a real growth area and, as with any product or service, it’s sometimes difficult to work out the cowboys from the cavalry.
Tests are particularly difficult in this respect. What defines a good test is the research and data behind the questions just as the design of a computer says nothing about the quality of the software or the processor. Internet-delivered tests are a particular problem since the “sexiness” of their design is beguiling but many of them provide no evidence that they’re any good.
A good psychometric test will be absolutely transparent to you as a user. It will state how it was developed, how many people it was tried on, where it should be used and where not and, most importantly, how much you can trust the results.