The most accurate 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 were concerned that a bill of rights could imply that any unenumerated rights were not protected, thus potentially limiting rights, whereas Anti-Federalists believed that a formal declaration of rights was necessary to safeguard individual liberties against potential government overreach.