After three days of talks, leaders of the major industrial nations can honestly claim that the annual economic summit they concluded Tuesday in Toronto fully lived up to expectations.

Which is to say that, since those expectations never were particularly high, the summit was long on self-congratulation but short on accomplishment. The final official communique summing up the summit could just as easily have been produced days or even weeks ago, instead of shortly before adjournment.After congratulating each other on their strong economies, the leaders of the U.S., Britain, Canada, France, Italy, Japan, and West Germany spent most of the time tiptoeing around thorny political problems.

Dismayed by the military coup in Haiti, the seven leaders reacted cautiously, unwilling to condemn it unilaterally.

Likewise, they waffled on sanctions against South Africa and could not agree how to get Vietnamese troops out of Cambodia or what to do about the increase in Arab-Israeli violence in the Middle East except to call for a peace conference.

Reciting their respective standard positions on touchy subjects, they were unanimous in the need for closer East-West ties, issued a meaningless call to fight terrorism by keeping hijacked planes grounded except when hostages were endangered, and backed a U.S. plan for an international task force to combat drug trafficking. But the plan leaves many questions unanswered, including the date for setting up the task force and who would belong to it.

While extolling the virtues of economic cooperation, the summit did little to further it. Though the seven leaders agreed that the $200 billion spent each year on farm subsidies constitutes a severe drain on their economies, they again spurned President Reagan's call to phase out the subsidies. Likewise, though the appalling $1.2 trillion debt of Third World nations keeps growing, a united way of dealing with it still eludes the economic summit.

Clearly, the Toronto summit lacked a sense of urgency, and that's understandable - up to a point. After all, the threat of a global recession seems much more remote than it did a year ago, America's trade deficit is coming down, the dollar is stable for the moment, and the major industrial nations are generally prospering.

Even so, the persistent failure to come to grips with such problems as Third World debt and farm subsidies is disturbing. The summit seems to be in the position of saying it can't fix the hole in the roof when it's raining and doesn't feel the need for repairs when the sun is shining. The longer the economic summit embraces this policy of drift, the more it runs the risk of encountering much worse problems later.