You need to have indexing installed, it is a seperate component. Then you need to index your database. Then you can do keyword searches. For things like Creo objects or Windchill parts, I beleive it reads the header information which includes attributes. For office documents and PDFs that are not vectors, it will index the 1MB of text. There is a whole list of files that it will index.
Version and context should not be keyword searches, but are related to Windchill versioning scheme and the contexts you have created.
Hope this helps.