With all due respect, the concept of the class becomes painfully clear when you read it. I try to avoid bogging down base classes with fluff, as the more open-ended they are, the wider the range of character concepts they can fit into. See fighter vs paladin for an example.
However, in a nutshell, the class is intended to fill a party support role, with wide-ranging buffs and light healing capabilities, while still being useful at combat if the character decides to go that route. Shouts provide quick effects that still allow the Paragon to wade into the fray, while chants detract from her ability to attack while providing additional party-wide bonuses.