What do the texts actually say about the Anunnaki?

The safest starting point is that the Anunnaki are a group of gods in Mesopotamian texts. Their roles and relationships are not described the same way in every source, so there is no single, fixed account to extract from all the tablets.

The texts belong to different periods and genres, too. A myth, hymn, or ritual text is doing different work, and it should not automatically be read as a report of historical events.

The alien reading is a modern claim, not what the surviving texts straightforwardly say. The Anunnaki are presented as deities, not as extraterrestrial visitors, and specialist readings of the ancient languages do not support the popular claims about them arriving in spacecraft or mining Earth for resources.

Zecharia Sitchin helped spread that interpretation, but his translations and conclusions are not accepted by specialists in Sumerian and Akkadian. It is fair to discuss his influence, but his version should not be mistaken for a direct translation of the tablets.

I would separate two questions: what the texts say within their religious and literary worlds, and what evidence they offer about real events. The first can be studied through the wording and context. The second needs independent historical evidence, not just a dramatic modern reading of a deity's name.

Also, calling a text a myth does not mean it was meaningless to the people who made or used it. It just means we should be careful about treating its divine characters as a record of ordinary human history.