The Metropolitan Opera's week at Wolf Trap got off to an uneven opening last night with Puccini's "Tosca."

In the end it boiled down to a production that the company would not put on the stage at Lincoln Center, though some of its virtues would look and sound handsome enough for any house. James Conlon conducted strongly, holding together performers who sounded as if they were not too well acquainted with all the details.

Leonie Rysanek, remembered for her fiery Tosca here several seasons ago with the Deutsche Oper, was again one of the more melodramatic actresses in the famous rol e, a train-kicker and wall-climber in whom you could believe every minute.

But she is not one of the Met's regular Toscas in New York City, where she sings more German than Italian opera. In the earlier scenes, she made things difficult for Conlon in the way she opened her tones slowly, while the tenor, Vasile Moldoveanu, delivered his notes right on the beat - no subtlety, but right on the nose.

But when Rysanek got together with Cornell MacNeil's Scarpia for one of the steamier second acts, the pressure cooker really worked. She is an all-out actress who does not let minor details like falling fans stop her. Things did not quite jell in moments like her over-prolonged holding of the wine glass which she smashed as she picked up the knife to stab Scarpia. The timing was off, but the end result was as effective as ever.

Her portrait was filled with expert details. For example, when Scarpia came up behind her and touched her bare arm in Act Two, just before sitting down to write out her safe conduct, she really did look as if she would throw up at the mere contact.

MacNeil plays superbly opposite such a Tosca. His obvious sadistic delight at the beginning of the torture scene was as subtly conveyed as his instant scheme for trapping Tosca with the Attavanti fan in the first act. His lower voice may be dry, but MacNeil has the grand role in his system clear to the ends of his fingertips.

All of this richness of character acting is missing in Moldoveanu. He has a handsome voice which he sometimes uses well. As an actor he is a cipher, who looks straight at the conductor, and sings right at the audience. Did he not even notice how often MacNeil and Rysanek sang with their backs to the orchestra? Someone should coach the young man.

He moved without urgency when saving Angelotti's life; he ignored his painting while singing about it. Voice is by no means enough.

The rest of the production was enhanced by Andrea Velis, who makes Spoletta truly loathsome with his expert touches, and Italo Tajo, whose Sacristan, aside from uncalled-for choral conducting at the end of Act One, was richly done. Where were the choir boys in Act One? Their absence was only one of the elements that caused that entire finale to fall flat.

In New York City latecomers to the Met are seated at the ends of the acts. Why should they be treated any differently at Wolf Trap, where they are allowed to walk in front of the thousands who are there on time? There was a huge audience last night which applauded very perspicaciously. CAPTION: Picture, From Act I of the Metropolitan's "Tosca"