The WebSearch tool has a system-level mandate to append a Sources:
section at the end of every response. SKILL.md's old "DO NOT output
Sources: list" instruction was too weak to override it.
Fix: redirect citations into the stats block's Web: line as inline
links. The WebSearch citation requirement is satisfied there; an
explicit note after the stats block tells the model not to append
a separate trailing section.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>