The correct contrast between Federalists' and Anti-Federalists' understandings of what a bill of rights would do in the Constitution is:
Federalists saw a bill of rights as a document that would limit people’s rights, while Anti-Federalists saw such a document as preserving the most important rights.
Federalists argued that a bill of rights was unnecessary because the Constitution itself did not grant the government the power to infringe upon individual liberties, while Anti-Federalists believed that a bill of rights was essential to protect individuals from potential government overreach.