diff --git a/atlasbot/engine/answerer.py b/atlasbot/engine/answerer.py
index ad42928..0272908 100644
--- a/atlasbot/engine/answerer.py
+++ b/atlasbot/engine/answerer.py
@@ -1304,6 +1304,8 @@ async def _select_metric_chunks(
         tag="metric_keys",
     )
     selected = _parse_key_list(raw, available_keys, max_keys)
+    if candidate_keys:
+        selected = _merge_metric_keys(selected, candidate_keys, max_keys)
     if not selected and candidate_keys:
         selected = candidate_keys[:max_keys]
     if not selected:
@@ -1408,6 +1410,22 @@ def _lines_for_metric_keys(lines: list[str], keys: list[str], max_lines: int = 0
     return selected
 
 
+def _merge_metric_keys(current: list[str], candidates: list[str], max_keys: int) -> list[str]:
+    merged: list[str] = []
+    seen = set()
+    for key in current:
+        if key and key not in seen:
+            merged.append(key)
+            seen.add(key)
+    for key in candidates:
+        if key and key not in seen:
+            merged.append(key)
+            seen.add(key)
+        if len(merged) >= max_keys:
+            break
+    return merged[:max_keys]
+
+
 def _merge_fact_lines(primary: list[str], fallback: list[str]) -> list[str]:
     seen = set()
     merged: list[str] = []