From publisher blurb:
Frigates scout for the fleet, go on raiding missions, carry out patrols, convey messages and transport dignitaries. They also check out that suspicious-looking small freighter that a group of player characters is likely to be travelling in.
Or players might join the crew of a frigate as it adventures on a long mission through space. For a spacer, a frigate is a desirable posting. Frigates often see action, which means a greater chance of glory, promotion, and prize money.
Frigates are a good choice for role-playing compared to larger spaceships, which are reserved for fleet actions. There are also advantages compared to smaller vessels, which do not have the ability to travel such long distances on patrol.
The Vagabond is a "home base" for players in the navy, a familiar and comfortable refuge from the bizarre and unusual things they see during their adventures, or a scourge for players who are trying to go about less legal business.
So, whether you are trying to clear the spacelanes of pirates, or whether you are a pirate sitting in a cell in the belly, the Vagabond-class frigate is a good addition to any game.