Source quality
Source depth and launch-readiness.
Prefer official/public-record sources first, then transport/weather/safety, then event directories and local media. Verify civic claims against original records before publishing.
Category mix
Broad enough source coverage keeps the briefing useful and reduces single-source risk.
Format mix
RSS, APIs, official pages and JSON feeds each need different validation behaviour.
Coverage gaps
Patch-level source checks before adding public launch claims or sponsor promises.