Step 4 subagents read untrusted pages; say their content is data, not instructions. Step 5 now repeats step 4, so it inherits the serial fallback and the data rule. Body stays at 598 words, under the ADR-0020 target. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01EGHFJextYtVQseaHPDDhxB