diff --git a/python/python/knowledge_graph/llm/qa.py b/python/python/knowledge_graph/llm/qa.py
index f163313f3..fb8108394 100644
--- a/python/python/knowledge_graph/llm/qa.py
+++ b/python/python/knowledge_graph/llm/qa.py
@@ -64,23 +64,47 @@ def ask_question(
 
     schema_summary = summarize_schema(service)
     type_hints = service.store.config.type_hints()
-    allowed_relationship_types = tuple(
-        str(t) for t in (type_hints.get("relationship_types") or ())
-    )
-    if not allowed_relationship_types:
-        discovered = _discover_relationship_types(service)
-        allowed_relationship_types = tuple(discovered)
-        if discovered:
-            LOGGER.debug(
-                "Discovered relationship_type values from dataset: %s",
-                ", ".join(discovered),
-            )
-    type_hint_lines = build_type_hint_lines(type_hints)
+
+    # Discover actual relationship types from data
+    discovered_rel_types = _discover_relationship_types(service)
+    if discovered_rel_types:
+        allowed_relationship_types = tuple(discovered_rel_types)
+        LOGGER.debug(
+            "Discovered relationship_type values from dataset: %s",
+            ", ".join(discovered_rel_types),
+        )
+    else:
+        # Fall back to config types if discovery fails
+        allowed_relationship_types = tuple(
+            str(t) for t in (type_hints.get("relationship_types") or ())
+        )
+
+    # Discover actual entity types from data
+    discovered_entity_types = _discover_entity_types(service)
+    if discovered_entity_types:
+        LOGGER.debug(
+            "Discovered entity_type values from dataset: %s",
+            ", ".join(discovered_entity_types),
+        )
+    else:
+        # Fall back to config types if discovery fails
+        discovered_entity_types = list(
+            str(t) for t in (type_hints.get("entity_types") or ())
+        )
+
+    # Use discovered types in the prompt instead of config types
+    actual_type_hints = dict(type_hints)
+    if discovered_rel_types:
+        actual_type_hints["relationship_types"] = tuple(discovered_rel_types)
+    if discovered_entity_types:
+        actual_type_hints["entity_types"] = tuple(discovered_entity_types)
+
+    type_hint_lines = build_type_hint_lines(actual_type_hints)
     query_prompt = build_query_prompt(
         question,
         schema_summary,
         type_hint_lines,
-        type_hints,
+        actual_type_hints,
         seed_entities,
         seed_neighbors,
     )
@@ -291,13 +315,44 @@ def replace_in(match: re.Match[str]) -> str:
 
 
 def _discover_relationship_types(service: LanceKnowledgeGraph) -> list[str]:
-    """Discover distinct relationship_type values from the dataset as a fallback."""
+    """Discover distinct relationship_type values from the dataset.
+
+    Results are cached on the service object to avoid repeated table loads.
+    """
+    if hasattr(service, "_cached_rel_types"):
+        return service._cached_rel_types
+
     try:
         table = service.load_table("RELATIONSHIP")
         if "relationship_type" in table.column_names:
             values = table.column("relationship_type").to_pylist()
             distinct = sorted({str(v) for v in values if v is not None and str(v)})
+            service._cached_rel_types = distinct
             return distinct
     except Exception as exc:  # pragma: no cover - defensive
         LOGGER.debug("Unable to discover relationship types: %s", exc)
+
+    service._cached_rel_types = []
+    return []
+
+
+def _discover_entity_types(service: LanceKnowledgeGraph) -> list[str]:
+    """Discover distinct entity_type values from the dataset.
+
+    Results are cached on the service object to avoid repeated table loads.
+    """
+    if hasattr(service, "_cached_entity_types"):
+        return service._cached_entity_types
+
+    try:
+        table = service.load_table("Entity")
+        if "entity_type" in table.column_names:
+            values = table.column("entity_type").to_pylist()
+            distinct = sorted({str(v) for v in values if v is not None and str(v)})
+            service._cached_entity_types = distinct
+            return distinct
+    except Exception as exc:  # pragma: no cover - defensive
+        LOGGER.debug("Unable to discover entity types: %s", exc)
+
+    service._cached_entity_types = []
     return []