Updated contributing guide (#6843)

Author: katharinalisalin

docs/contributing/index.md

@@ -253,4 +253,17 @@ organized.
     not yet received a response to their issue/question, as the issue is marked as
     incomplete.
 
+  - __Limitations of automated tools:__  While we believe in the value and
+  efficiency that automated tools bring to identifying potential issues (such
+  as those identified by Lighthouse, Accessibility tools, and others), simply
+  submitting an issue generated by these tools does not constitute a complete
+  bug report. These tools sometimes produce verbose outputs and may include
+  false positives, which necessitate a critical evaluation. You are of course
+  welcome to attach generated reports to your issue. However, this does not
+  substitute the requirement for a minimal reproduction or a thorough discussion
+  of the findings. _We reserve the right to mark these issues as incomplete and
+  close them._ This practice ensures that we are addressing genuine concerns
+  with precision and clarity, rather than navigating through extensive automated
+  outputs.
+
   [minimal reproductions]: ../guides/creating-a-reproduction.md