A good user story is a promise of a conversation, not a full specification. Developers appreciate stories that explain the why clearly and leave room for them to propose the how.
Use a simple format: as a type of user, I want a capability, so that I get a benefit. The "so that" clause is the most important part; it lets the team suggest simpler solutions that still meet the goal.
Add concrete acceptance criteria. Given-when-then statements or a short checklist make it obvious when the story is done and give testers something specific to verify.
Keep stories small enough to finish in a few days. If a story needs multiple teams or weeks of work, split it by workflow step, user type, or data variation. And always include an example: one realistic scenario removes more ambiguity than a page of abstract requirements.
