The Document Search Build Tool creates an Object with a list of values that are pre-supplied text documents or paragraphs and uses another Object to capture the input text which is 'searched' against these pre-supplied values to find the top match.
For example this could be used where there are a 'golden set' of documents like identity documents (driving licence, passport, utility bill) and the runtime is provided with the content of a user's identity document and the system needs to determine which one is the closest match from its 'golden set'.