diff --git a/api/clarify.py b/api/clarify.py
index 87834009..8ad750ac 100644
--- a/api/clarify.py
+++ b/api/clarify.py
@@ -122,6 +122,11 @@ def submit_pending(session_key: str, data: dict) -> _ClarifyEntry:
                 == list(data.get("choices_offered") or [])
             ):
                 entry = last
+                # Dedup re-uses the existing entry with its original clarify_id.
+                # If a future caller pre-populates clarify_id in data, it is
+                # silently discarded here — the original entry's id wins.
+                # Today no caller sets clarify_id (it's generated by __init__),
+                # so this is a non-issue.
                 cb = _gateway_notify_cbs.get(session_key)
                 # Keep _pending aligned to the oldest unresolved entry.
                 _pending[session_key] = gw_queue[0].data
diff --git a/api/routes.py b/api/routes.py
index 5a523d19..af6599dc 100644
--- a/api/routes.py
+++ b/api/routes.py
@@ -9080,6 +9080,9 @@ def _handle_clarify_respond(handler, body):
         ok = _resolve_clarify_legacy(sid, clarify_id, response)
 
     if not ok:
+        # Both the runtime adapter and legacy paths set ok=False for
+        # stale/expired/wrong-session responses.  The 409 status applies
+        # uniformly regardless of which path resolved the clarify request.
         return j(handler, {
             "ok": False,
             "error": "Clarification prompt expired or not found. The agent may have already proceeded.",