diff --git a/src/subconscious/agents/digest.agent b/src/subconscious/agents/digest.agent
index abdbd1c..efe4bc6 100644
--- a/src/subconscious/agents/digest.agent
+++ b/src/subconscious/agents/digest.agent
@@ -23,7 +23,11 @@ summaries into weekly ones.
 2. Read the undigested entries with `journal_tail` (level 0, after
    the last digest date).
 
-3. Write the digest with `journal_new` using the appropriate level:
+3. Check if the most recent digest at this level should be updated
+   (same date/week/month) — if so, use `journal_update` with the
+   appropriate level to append to it.
+
+4. If starting a new period, use `journal_new` with the level:
    - level=1 for daily digests
    - level=2 for weekly digests
    - level=3 for monthly digests