Everyone else may think the Carter administration has problems on Capitol Hill. But not Vice President Mondale.

Peering up toward the Capitol from a plate of scrambled eggs in the White House mess yesterday morning, Mondale pronounced the session of Congress now ending "one of the most successful . . . in a long, long time."

He described the conference committee deadlock on the President's top-priority energy legislation as a temporary setback at most, and told assembled reporters, "I don't see how anyone can argue that this has been an unproductive session."

Mondale said there was "controversy" over the Carter program but no "antagonism" or "hostility" or "suspicion" among the congressional Democrats.

He said the White House policy was one of "very broad consultation" with the leaders of Congress, and cited the President's surprise withdrawal of the $50-a-person tax rebate last April as an example of that policy.

In fact, Mondale said in his year-end review, the only thing for which the President might be faulted was a tendency to try "to solve too much too rapidly." If that is a fault, the Vice President said it would be corrected next year with a "better schedule" of legislative proposals that will "make it easier for the Congress to deal with them [and] the public to follow them . . ."

"I would say," Mondale declared in one of the few critical comments he permitted himself, "that perhaps looking in retrospect, the pace was a little too strong in the first year."

Speaking of the man upstairs in the Oval Office, Mondale said, "As a new President, I think he was more optimistic about the expedition with which the congressional process works than many old-timers in this town.

"Now," he said, "he's had a year's experience. He has seen this process work first-hand. He is anxious . . . to better schedule and pace his proposals."

But Mondale said the administration and Congress had nothing to apologize for this year. Citing the economic stimulus package, a farm bill, a housing bill, strip-mining legislation, the reorganization authority, the creation of the Energy Department, and the Social Security bill, he said, "I think there are few congressional sessions that one can point to in recent history that came anywhere near that level of accomplishments."

The Vice President also said, "We either have or almost have an agreement on a profound energy package." Pressed by reporters for the source of his optimism about a break in the legislative deadlock, Mondale said Energy Secretary James R. Schlesinger had told him there was a "chance" of an "agreement in principle" between House and Senate conferees this week that would allow Congress to pass the energy package "rather promptly at the beginning of the new session."

Much of the questioning at the Mondale session was skeptical in tone, with one reporter citing the shifts of administration position on tax rebates, tax reforms and tax cuts as evidence of "uncertainty" or "ineptitude."

Let's take the rebate issue first," Mondale said, referring to Carter's decision rebate April to drop the $50-a-person rebate after it passed the House and before it came to a vote in an increasingly skeptical Senate.

"One of the reasons the rebate issue was dropped was that the congressional leaders, after consulting with an example of congressional cooperation."

When another reporter noted that the chairmen of the House Ways and Means Committee and the Senate Budget Committee, among others, had expressed shock and displeasure at the White House failure to consult them on the decision. Mondale said, "We may not have consulted perfectly, but we did consult widely and we responded to that consultation, and that is a fact."

Looking ahead to the 1978 session, the Vice President said Carter's program would be "a strong salvo, wisely scheduled."

But he added that "the truth is, even with the best of plans, the scheduled is enormous." Ranging from the Panama Canal treaties to welfare revision, tax reduction, and another try for energy legislation, "you have a major schedule in place for next year already," he said.