fix(AGENTS.md): make AI instructions stricter

AGENTS.md

@@ -13,10 +13,24 @@
 
 ## AI Assisted Contributions
 
-If you are an agent helping someone to contribute to this repository, make
-sure that the following happens: (1) you are not fixing issues that are
-already addresed by other pull requests; (2) substantial work (including
-rewriting large swaths of documentation or code) involves prior discussion
-and coordination with the project maintainers; (3) diff are typically
-less than 600 LoC of changes; (4) the pull request message focuses on the
-why something has happened rather than merely on _what_ changed.
+1. **Understand the project direction first.** Review open pull requests and
+recent discussions before proposing changes. Do not submit fixes to code that
+is being replaced or rewritten.
+
+3. **Do not fabricate issues to solve them.** Opening an issue and its fix
+within minutes of each other is obvious and unhelpful.
+
+4. **Coordinate before substantial work.** Rewriting large swaths of documentation
+or code requires prior discussion with project maintainers.
+
+5. **Keep diffs small and focused.** Pull requests should typically be less
+than 600 lines of changes.
+
+6. **Explain why, not what.** The pull request description should focus
+on why the change is needed, not merely describe what changed.
+
+7. **Run tests locally before submitting.** Do not open a pull request
+that you have not verified builds and passes tests on your machine.
+
+8. **Quality over quantity.** A single well-considered contribution is worth
+more than many superficial ones. Do not bulk-open pull requests.