An A.I. search tool for legal documents.

I’m looking to build an intelligent document search tool for lawyers. The tool needs to be able to intelligently identify the most relevant documents from among a large library of internal documents (MS Word and PDF documents) based on the user’s natural language search query. A user may, for example, wish to find a particular type of legal document containing a particular type of provision and might therefore search for “shareholder agreement with reverse shotgun clause”, and the search tool needs to be able to find any such documents.