"Validation tools" are tools or methods used to check if something is correct, acceptable, or meets a certain standard or criteria. They help to confirm the accuracy, quality, or reliability of something. Full definition
The general reading public, your local bookstores and libraries need to know of this new validation tool on which self - published author can star relying right now. (thecreativepenn.com)
But Nick Walter used it as a market validation tool. (entrepreneur.com)