Annadif was born in Arada, Chad to a Rizeigat Arab family of the Mahariya branch and holds an engineering degree in telecommunications from the Polytechnic School of Madagascar.

During his time in office, Annadif implemented disciplinary measures after Human Rights Watch had revealed that African Union soldiers in Somalia raped and sexually exploited women and girls on their peacekeeping bases in the Somali capital Mogadishu.

[9] In December 2015, Annadif was appointed by United Nations Secretary-General Ban Ki-moon to serve as his Special Representative for Mali and Head of the United Nations Multidimensional Integrated Stabilization Mission in Mali (MINUSMA),[10] replacing Mongi Hamdi who had resigned after just a year amid difficulties implementing a peace deal and improving security in the north of the country.

[11] During Annadif's time in office, al-Qaeda in the Islamic Maghreb (AQIM) launched an attack in May 2016 on two United Nations' sites in northern Mali where a peacekeeper from China and three civilians were killed and over a dozen others wounded.

[12] Shortly after, the UN Security Council decided to send 2,500 extra peacekeepers to Mali, authorizing the force to take "all necessary means" to deter attacks.