Is there any tool or inbuilt utility in WebMethods to seach the documents on the broker ?
I dont know of a tool to search for documents on the broker but you can write a a Broker client that searchs a given broker for a specific document type using the java or c++ Broker client API.
BrokerClientJavaAPIProgrammersGuide.pdf, BrokerClientCAPIProgrammersGuide.pdf will help to write the code.
You can use a software called DOCUMENT TRACKER, it’s not provided by webMethods. You try in advantage site.