Strong collaboration and communication with your development partners is very important to the Agile process. But, remember that in your role there are some important quality assurance questions that you should ask yourself to keep your processes consistent.
WHY ARE YOU ONLY TESTING WHAT THE USER STORY TELLS YOU?
User stories should have acceptance criteria added by a product owner or business analyst. These are usually helpful for QA to know when they can consider a story as “Passed QA.” However, it’s important not to just stick to the AC and test only the “Happy Path” for a feature. The AC usually tells us what we want to happen, but it’s our job as testers to think about what could happen. Remember to use your QA skills to think outside the box and run validation and negative tests to improve your test coverage on a story.