The Kennedy Center has scheduled five plays--including the long-running Broadway drama "Agnes of God" and the hit London farce "Noises Off"--as part of the upcoming season in the Eisenhower Theater, according to an announcement yesterday by Roger L. Stevens, the Center's chairman.

The series will open on Sept. 15 with "The Golden Age," a new play by A.R. Gurney Jr., the author of such recent off-Broadway successes as "The Dining Room" and "The Middle Ages," which profile the slow erosion of the crisp world of the upper-middle classes. Gurney's latest play looks at the last weeks in the life of an aging New York grande dame, to be played by Irene Worth. John Tillinger will direct.

It will be followed in mid-October by the pre-Broadway tryout of Michael Frayn's "Noises Off," a farce that details the calamities that befall a third-rate theater troupe as it tours the English provinces with an idiotic sex farce, titled "Nothing On." Michael Blakemore, who staged the original production, will also stage the American edition; Dorothy Loudon, Brian Murray, Victor Garber, Amy Wright and Douglas Seale will be featured in the cast. The Frayn/Blakemore team was last represented at the Kennedy Center with the comedy "Make and Break."

"A Perfect Marriage," a drama by Ruth Wolf about the relationship between poet Percy Bysshe Shelley and his novelist wife Mary, will open early in December. A fantasy with feminist overtones, the action takes place initially on earth, and then moves on to heaven and to hell. The play will receive its break-in at the Hartman Theater Company in Stamford, Conn., before playing the Eisenhower.

Elizabeth Ashley will recreate her role as the chain-smoking psychiatrist in the national company of John Peilmeier's "Agnes of God." The three-character drama explores the mystery, both religious and profane, of a young nun who has given birth to a child, which she may then have strangled. Maryann Plunkett will play the nun and Mercedes McCambridge will be the mother superior who tries to protect the nun from the probings of the psychiatrist. The drama will open the second week of January.

Beginning in mid-February will be "Toes," a play by Anne B. Ellwood about a successful playwright whose characters are so real to her that she ends up having affairs with them in her imagination--to the abiding frustration of her manager. Toes is the Irish music hall performer who springs from her pages and materializes before her eyes. Yet to be cast, the play is being coproduced with Craig Anderson, formerly of the Hudson Theatre Guild.

The Center plans to offer a variety of subscription plans for the five works, plus a yet to be announced sixth. All the plays will have five-week runs, with the exception of "Noises Off," which is scheduled for six weeks.