With its sail-shaped design, Boston’s newest skyscraper is a 31-story invitation to the city’s newest gathering spot on the water.

The glass-walled tower at the corner of Congress Street and Atlantic Avenue is the largest development yet in a decades-long effort to transform the Fort Point Channel into a contemporary waterfront with residences, restaurants, boating tours, and cultural institutions.

And in addition to being one of the few to open during a slowdown in the commercial building sector, the $550 million Atlantic Wharf complex will probably be the last large property built on the downtown side of the city’s waterfront for some time. Boston Mayor Thomas M. Menino last year moved to restrict the size of buildings along the new Rose Fitzgerald Kennedy Greenway, just inland from the channel and waterfront.

Yesterday, developer Boston Properties announced the latest additions to the complex: steakhouse Smith & Wollensky and the Boston Society of Architects, which will also run architecture tours in the area from its new offices.

“It’s all about activating this space for the public,’’ said Michael Cantalupa, a Boston Properties executive. “You can expect performances, art and architecture, and restaurants that will spill onto the plaza.’’

The property features an expansive plaza on the waterfront and a series of new docks that will allow for water-taxi service, tour boats, and private docking for small vessels.

Later this month the building’s first major office tenant, investment firm Wellington Management, will begin moving into the 18 floors of space it has leased in the complex.

Over years of planning, Boston Properties made multiple revisions to Atlantic Wharf, most significantly reducing the number of residences there to 86, from 165 units, while increasing the amount of office space.