Here is an overview of each game, via the Xbox Games Store:
Metal Gear Solid 2: Sons of Liberty HD Edition
2007-2009: Manhattan Tanker Incident and Big Shell Incident After the Shadow Moses incident, technological data on the nuclear-armed walking tank “Metal Gear” leaks onto the black market. Solid Snake and his allies form the anti-Metal Gear NGO “Philanthropy” and set out in pursuit of a tanker carrying a new Metal Gear prototype. But Snake falls into a trap set by former FOXHOUND member Ocelot, and is believed lost along with the tanker at the bottom of the Hudson River. Two years later, the Big Shell, an oil spill cleanup facility constructed on the bay, is taken over by terrorists led by a man claiming to be the long-lost Solid Snake. The government sends Raiden, a new recruit in the new FOXHOUND, to infiltrate the Big Shell and rescue the US President, who is held hostage inside…
Metal Gear Solid 3: Snake Eater HD Edition
1964: Virtuous Mission and Operation Snake Eater The origin of the Metal Gear series begins in 1964 at the height of the Cold War. Naked Snake—the man who would later become the legendary soldier known as Big Boss—heads into Soviet territory to help the scientist Sokolov defect to the West. However, the mission ends in failure when Snake’s mentor, a female soldier known as The Boss unexpectedly defects to the Soviet Union. The fate of the world hanging in the balance, Snake is forced to question the true meaning of “loyalty,” as he embarks on a lone mission to kill his former mentor.
The Games on Demand version supports English, French, Spanish.