The Foreign Secretary said the Employment Pact aimed to promote macro- economic policy built around growth and stability.
But Mr Cook insisted the agreement would not bind national governments to any moves towards harmonisation of wages or taxes.
Opening a debate on the European Union, he set out the Government's conditions for reforming the European Commission.
He said modernisation proposals would be judged by whether they tackled the "endemic weaknesses" of Commission practice.
"We will be demanding that the management of the Commission matches up to the best standards in public administration," he said.
The summit comes after the entire Commission was forced to resign amid disclosures of financial mismanagement.
Mr Cook said the Government would demand promotion based on merit, contracts awarded by open procedures and "robust" measures against fraud, .
He added Britain would use the summit "to affirm" member states' joint resolve to complete Nato's military action against Yugoslavia.
Member states would have to ensure that Europe had both the capability to take responsible decisions on security and the military capacity to carry out these decisions. However, Mr Cook insisted there was no intention to usurp the role of Nato.
Dismissing proposals for the Employment Pact, the shadow Home Secretary, Michael Howard, said: "If the governments of Europe were serious about taking action to reduce the number of people without jobs in Europe - more than 16 million of them - they would be spending their time discussing how to cut down regulations and red tape.
"Instead they will be discussing the so-called employment pact, which should be renamed the unemployment pact. It contains more of the policies which have created Europe's tragic levels of unemployment in the first place."Reuse content