Agile: what does the analyst need to know for action?

Quite regularly you hear questions like the following: "We have a Scrum project, I need to write test cases for the testers, and I do not understand where I get information from." When you start to discuss, it turns out often that the word "Scrum" in the project they know some original design, while the inquirer is precisely sure that this is exactly Scrum. Meanwhile, Scrum and other Agile methods are a normalized model, about which you can read the documents, and from which you can get answers to this and other questions. But I will not provide the documents. I will show how to think in the logic of Agile mindset, get answers to this and other issues. Of course, as long as such values of the Agile Manifesto as working software, cooperation with customers and others do not seem to be a mere sound. I will show everything on real cases from listeners, solving their problems.