When Mr. Cuomo and legislative leaders announced an agreement on the ethics overhaul in a statement on Friday, they issued only a summary of the changes, refusing to release the actual bill. Their reluctance to do so kindled suspicions that the fine print contained concessions to legislative leaders.

On Tuesday, several new wrinkles became apparent with the release of the legislation. The State Senate majority leader, Dean G. Skelos, a Long Island Republican, and the Assembly speaker, Sheldon Silver, a Manhattan Democrat, permanently enshrined their caucuses’ powers over ethics enforcement, even if their legislative majorities are ousted.

Commissioners appointed to a 14-member ethics oversight board proposed in the legislation could vote 12 to 2 in favor of an investigation of the executive branch and still lose. An 11-to-3 vote in favor of an investigation of a legislator could also fail.

Such were the oddities that emerged in the 113-page bill. State officials argued that the legislation was a significant step forward in strengthening ethics regulations and that it went to great lengths to be fair to both major parties. The bill is supported by government watchdog groups, which say it is an improvement over the Legislature’s almost nonexistent ethics enforcement and have praised the bill’s tougher disclosure rules.

“This bill takes the unprecedented step of providing independent oversight of both branches of government under one commission,” said Josh Vlasto, a spokesman for Mr. Cuomo, a Democrat. “Checks and balances, both between the branches and between the parties to avoid partisan witch hunts, are essential.”

But the bill’s full draft revealed unusual features.

Two of the three Democratic appointees the governor would make to the new ethics board could block an investigation of a statewide elected official or executive branch appointee. That means the commission could vote 12 to 2 in favor of an investigation into the executive branch and the vote could still fail. Over all, the governor would appoint six commissioners: three Democrats and three Republicans.

The legislation grants permanent powers to the existing legislative majorities. Specifically, if the narrowly divided Senate ever returned to Democratic control, Republicans would continue to appoint three of the four commissioners named by the Senate. The same goes in the Assembly, even if the Democrats, who hold a 95-to-51 edge there, ever lose their wide advantage.

The arrangement would permanently curtail the powers of the current legislative minorities with respect to ethics enforcement.

“Sounds like Dean wrote that,” Assemblyman Brian M. Kolb of Canandaigua, the leader of the Assembly Republican minority, joked, referring to Mr. Skelos, the most powerful Republican in the Legislature. “I don’t see how they could keep their appointments. I’m tongue-tied about that.”

Austin Shafran, a spokesman for Senate Democrats, who hold 30 of the 62 seats in the chamber, said Senator John L. Sampson of Brooklyn, the Democratic leader, had reservations about the deal.

“Senator Sampson supports the broad concepts behind the bill, but has concerns that permanent partisan control could detract from its independence and effectiveness,” Mr. Shafran said.

Scott Reif, a spokesman for the Senate Republicans, said, “We expect that this legislation will include safeguards to ensure that the commission operates in a bipartisan manner, and no one political party can unfairly target the other.”

Dick Dadey, executive director of Citizens Union, said, “Taking a roll of the dice with this complex and untested veto-producing structure was the price of admission needed to secure historic disclosure and first-ever external oversight.”

While the legislation requires lawmakers who are lawyers to begin disclosing their clients, it gives lawmakers time to prepare. It applies only to new clients brought in after July 2012, or new matters taken up for existing clients after July 2012.

There are also several exemptions. Chief among them, lawmakers do not have to reveal clients of their law firms who have business before the state if the lawmaker has not had direct dealings with that client. Earlier proposals had called for the disclosure of all legal clients with state business at firms that employ lawmakers.

Disclosure of lawmakers’ outside incomes appears to be robust. Under current law, legislators must select one of six income bands in which their outside earnings fall, but their selections are redacted from their ethics disclosure forms before they are released to the public.

The new ethics rules would do away with the redactions, and the draft bill replaces the six income bands with more than 100.