Personality Test aren't true evaluators for job success

I observed first hand, a situation that a very good candidate didn't get even through the first cut of a job screening process because of a "Personality Test".  These tests are called different things, but they are used and intended to judge the personality of a person and as a predictor how they will perform.

While discussing these tests with the vendors, you'll get a valid argument that they can be used as a tool for management to understand what motivates people differently.  I agree. But, too often they are used as a filtering tool.  Wrong move! 

Two main items that I believe points out their faults:  1) They can be manipulated.  Again the vendor will disagree, saying they use multiple questions to test traits that can't be tainted.  Again wrong.  I have had an opportunity to test this myself and have twisted answers to achieve desired traits in the results.  2) Companies must have a baseline as what traits make each role successful.  Again wrong.  In this industry, I have seen very successful personalities of all types as recruiters and sales people.  Now, I have seen certain successful companies only hire certain "types" of personalities that has proven successful.  But not a guarantee!

I believe the healthiest companies mirror their client base.  Meaning there are all types of personalities.  Don't pigeon people by these tests, and if you must use them, only make it part of your evaluations, not the main focus.