diff --git a/ops/extract-cron.sh b/ops/extract-cron.sh
index 53827cf..a08789d 100755
--- a/ops/extract-cron.sh
+++ b/ops/extract-cron.sh
@@ -2,10 +2,22 @@
 # Extract claims from unprocessed sources in inbox/archive/
 # Runs via cron on VPS every 15 minutes.
 #
+# Concurrency model:
+#   - Lockfile prevents overlapping runs
+#   - MAX_SOURCES=5 per cycle (works through backlog over multiple runs)
+#   - Sequential processing (one source at a time)
+#   - 50 sources landing at once = ~10 cron cycles to clear, not 50 parallel agents
+#
+# Domain routing:
+#   - Reads domain: field from source frontmatter
+#   - Maps to the domain agent (rio, clay, theseus, vida, astra, leo)
+#   - Runs extraction AS that agent — their territory, their extraction
+#   - Skips sources with status: processing (agent handling it themselves)
+#
 # Flow:
 #   1. Pull latest main
-#   2. Find sources with status: unprocessed
-#   3. For each: run Claude headless to extract claims
+#   2. Find sources with status: unprocessed (skip processing/processed/null-result)
+#   3. For each: run Claude headless to extract claims as the domain agent
 #   4. Commit extractions, push, open PR
 #   5. Update source status to processed
 #