Every commit must have a descriptive title and a substantive body. Title-only commit messages are not acceptable.
The body must explain the problem or motivation, what changed, and why the chosen approach addresses it. Include relevant behavior before and after the change, design decisions, limitations, and validation results. Scale the detail to the change; do not add boilerplate or claim checks that were not run.
Commit messages must stand on their own. Put the information needed to understand and review the change in the commit body, even when it also appears in a pull request description. PR and issue links may provide additional context, but must not substitute for that explanation.