Has human rights law done more good than harm or more harm than good?
The basis of human rights law is the United Nations's Universal Declaration of Human Rights, passed in 1948. The document recognizes certain human rights as fundamental to each and every person around the world, and the United Nations has worked to pass treaties that bind signatory countries to respecting these rights.
Human rights law has done a great deal of good in protecting the rights of people around the world, including people who live in nations without a tradition of democracy or respect for inalienable rights (meaning rights that can't be taken away from people). For example, human rights law has worked to stop human trafficking, which is the acquisition of people with the intention to exploit them (for purposes such as prostitution, forced labor, drug trafficking or other purposes). As these people are often brought from one country to another, their plight needs an international body such as the United Nations to publicize and fight it. This is a global problem that requires a global response.
Some might argue that human rights has done harm in not respecting local cultures. For example, the United Nations has conducted a campaign advocating zero tolerance for non-medical female genital mutilation (see the link below). The UN estimates that over 200 million women and girls today have undergone this process, which is done for traditional reasons in many parts of Africa. Someone with a western mind frame would likely condemn this practice, which causes health complications and even infertility in the girls who undergo it, but there is no doubt that the United Nations' program of human rights is a western model that exports western ideas to other parts of the world. You must decide whether human rights has done more harm than good, given its effects and program.