Literary agents act for and advise writers.
The agent's knowledge should include who, within a publishing house, journal office or production company, is responsible for what areas, who is interested in what genres and styles, how the decisions are made within a given company, what is currently selling well - the list goes on. Agents can advise a writer on the manuscript in terms of broad editorial direction, keeping these licensors or buyers in mind. When the publisher makes an offer for a manuscript or proposal it is the agent's role to negotiate offers and the other rights relating to publishing contract. Important contractual points for negotiation include which publication territories, as well as which associated, subsidiary and ancillary rights, will be included. There are many negotiable points in such a contract - what the points are and how they are negotiated varies widely.