In order to make a compromise, what rules does Brutus give Antony about what he can and cannot do in his speech at Caesar's funeral?

Brutus and his fellow conspirators know how much Caesar is loved by the Roman people. After the hero's brutal murder, the conspirators are deeply scared, fearful of what may happen next. The people need to be reassured, lest they rise up and overthrow the usurpers. Brutus plans to make a speech to the people emphasizing the tragic necessity of Caesar's death for the greater good of Rome. Mark Antony will also get a chance to speak. Though not a part of the conspiracy, he has wisely decided not to show his hand too soon and come out against the assassins.
Nevertheless, Brutus doesn't completely trust Mark Antony. He'll let him make a speech as it might help to soothe tensions, but he wants to make sure that Mark Antony won't in any way disparage the conspirators or incite open rebellion against them. He can praise Caesar, certainly, but criticizing Brutus and his fellow assassins is strictly out of the question.
Mark Antony does as he is bid. But in speaking to the people, he completely turns the tables on Brutus and the other conspirators. His speech is indeed a fulsome tribute to his fallen friend. But it is also a masterful feat of oratory guaranteed to turn the people against Caesar's assassins far more effectively than any rant or outspoken harangue could ever do.