Same here. Always tell them the way you want it done.

For example:

Instead of "don't modify the tests"

It should be: analyze the test output and fix the bug in the source code. The test is built correctly.

Not the best but you get the idea.

The one problem with this is if you don't know how to do something properly. Like if you're just writing in your prompt "generate 90% test coverage" , you give it a lot more leeway to do whatever it wants.

And that's how you end up with the source code being modified to fit the test vice versa