There are a few different types of tests that can be used to measure personality, and each has its own strengths and weaknesses.
The most common type of test is the questionnaire. Personality career test ask you to answer a series of questions about yourself, and they typically have a short time limit so you can't spend too much time on them.
The downside of questionnaires is that they're often difficult to score accurately. Because people tend to give different answers when they're forced into an assignment vs when they're giving their genuine opinion, questionnaires can be unreliable at predicting real-world outcomes.
Another type of test is the self-report measure. This type of test asks you to report your thoughts and feelings about a particular topic, rather than asking you to answer questions about it.
One advantage of self-report measures is that they're often easier to score accurately. Because people usually remember more personal information than questionnaires ask for, self-report measures are more reliable in predicting real-world outcomes.
However, self-report measures don't always provide as much detail as questionnaire measures do. This means that they might not be as effective at detecting subtle differences in personality traits.
The final type of test is the psychometric measure. Psychometric tests measure how well someone does on specific tasks related to personality traits, such as providing accurate responses to questions or solving puzzles correctly.