EU leaders have agreed to publish "stress tests" of banks next month to show investors where any potential risks lie.
EU Commission President Jose Manuel Barroso said the results would be published "on a bank by bank basis - this should reassure investors".
The announcement came after EU summit talks dominated by the debt burden weighing on many member states.
The EU is wrestling with Europe's worst public debt for decades.
Leaders are intent on preventing contagion from the Greek budget crisis.
The summit came amid particular concern about public finances in Spain, the fourth biggest eurozone economy.
Bank levy plan
"Stress tests of banks will be published at the latest in the second half of July," European Council President Herman Van Rompuy said.
On Wednesday, Spain published the results of stress tests showing how its financial institutions would behave in a future crisis.
Now, overcoming German reluctance, all EU countries said they would do the same. The BBC's Oana Lungescu in Brussels says it is an unprecedented move which they hope will restore market confidence in the battered euro.
The leaders also agreed on the need for a bank levy, to ensure that any future bail-out is funded mainly by banks, rather than taxpayers.
Although details remain unclear, they will urge the US and other major economic powers to embrace a bank levy system at the G20 summit next week.
"In the G20 we will also propose to explore and to develop the introduction of a financial transaction tax," Mr Van Rompuy said.
"There is no need to create new [EU] institutions, it is... a matter of working better together," he added.
Both he and Mr Barroso have spurned suggestions by German Chancellor Angela Merkel that EU treaty changes might be necessary to enforce budget discipline.
The EU leaders agreed on tighter collective supervision of individual member countries' budgets.
In addition, the rules governing debt levels among the 16 eurozone countries will be strengthened.
Earlier, British Prime Minister David Cameron, attending his first EU summit, promised to play a "positive" role in the bloc.
"We will of course always defend our national interests, as others do, and our national red lines," he added, speaking alongside Mr Barroso.
Both Mr Cameron and Mr Barroso said the EU should be focusing on "substance" rather than institutions.
At their early morning meeting Mr Barroso served up an English cooked breakfast of bacon, sausage and egg for Mr Cameron.
As the summit got under way the cost of borrowing for the Spanish government hit a record high, reflecting doubts about Spain's ability to repay its debts.
The government admitted this week that foreign banks were refusing to lend to some Spanish banks.
French President Nicolas Sarkozy insisted however that "there is no problem with Spain, we are showing full confidence in the Spanish authorities".
Spain has been forced to deny reports that it is in talks with the IMF over a bail-out package to help it manage its debts.
The country has announced budget cuts and unpopular labour reforms to avoid a Greek-style meltdown.
The eurozone has set up a 750bn-euro (£623bn; $920bn) bail-out mechanism as a safety net in case any more countries suffer a similar debt crisis to Greece.
The draft summit document mentions EU member states presenting their budgetary plans to the European Commission each spring, "taking account of national budgetary procedures", BBC Europe editor Gavin Hewitt reports.
The UK has made it clear that its budget must go before the British parliament before being presented to EU officials for scrutiny.
However, the UK's pre-budget report is already fed into EU finance ministers' discussions before the full budget appears in April, a UK diplomat told the BBC.
The EU leaders also discussed a new 10-year strategy for jobs and growth, drafted by the Commission, called "Europe 2020".
It sets out a range of targets for employment, training and investment. Spending on research and development would reach 3% of gross domestic product (GDP) under the plan.