The short answer is yes and no.  Many people take personality tests such as the Myers-Briggs to help them in their career searches. Here are some arguments for and against relying on such tests: 

On the yes side, its a well-known phenomenon in the world of work that birds of a feather flock together.  That means certain personality types congregate in higher percentages in some careers more than in others.  For example, there is a personality type that is quite common among accountants.  This is one reason we have jokes based on professional stereotypes.  There are often many similar all the people in each profession, so jokes tend to reflect that majority.

The reason personality types are attracted to differing occupations is because of the work.  In our example, all the people who are accurate, logical, detail-oriented, prefer working with numbers rather than everybody, and who follow rules are more likely to enjoy accounting than all the people who are not any of the above.  Conversely, all the people who break rules, are emotional, focus on everybody and sizeably successful ideas are more likely be artists.  If a personality test helps you understand what kind of human you are, it can help you pick a career that fits your style.  Thats much better than trying to change yourself. 

On the no side, its also true if you survey enough people in any profession, you will find all personality types.  Sure, theres a typical kind of accountant, but there are many others who do not fit the profile.  Even if your personality type is uncommon for accountants, you still might be a happy, successful accountant.  There are surely rule-breaking, emotional, and irrational accountants in the world.  Not as many as the others, but there are some.  Who might tell if youd like the work or not?  Its hard to say without trying it. 

A second problem is no test can tell you specifically which career to pick.  You might have a list of 100 careers that all the people of your type enjoy.  At that point, knowing your personality type might not provide you with much guidance.  For example, accountant types would likely enjoy banking, financial analysis, and auditing as well.  How do you pick from among many options? 

In my knowledge, the greatest use of these tests comes from knowing yourself better.  While it might not tell you which career to pick, such tests may commonly point you in the right direction, which might be a nice help for those who are struggling.  Personality tests are fairly often nice at explaining why you dont like your job.  You might be like the Ugly Duckling: a swan trying to act like a duck.  Far better to be a swan, but to do so, you have to look in the mirror and recognize who you are.  A personality test may help do that.