Tests and measures are categorized as published or unpublished.
Published tests are commercially available for purchase from a publisher and often may only be bought by a qualified or professionally credentialled user. The purchase often includes a manual to help you administer the test and interpret the data.
Unpublished or noncommercial tests are usually referred to in journal articles, dissertations, reports, etc.and are often made available for use by contacting the author. If you contact an author for permission to use their test you will have to ask for information on administration and how to interpret.
APA Definitions:
Validity--The degree to which empirical evidence and theoretical rationales support the adequacy and appropriateness of conclusions drawn from some form of assessment. Validity has multiple forms, depending on the research question and on the particular type of inference being made.
Reliability--The trustworthiness or consistency of a measure, that is, the degree to which a test or other measurement instrument is free of random error, yielding the same results across multiple applications to the same sample.