diff --git a/backend/app/services/chat/chat_orchestration_service.py b/backend/app/services/chat/chat_orchestration_service.py
index 11a343e..c850a37 100644
--- a/backend/app/services/chat/chat_orchestration_service.py
+++ b/backend/app/services/chat/chat_orchestration_service.py
@@ -60,6 +60,10 @@
 7. Every view is already scoped to the customer you are answering for -- it returns their rows and
    no one else's. Never reference `customer_id` in a `WHERE` clause and never invent an id value;
    there is no id for you to supply.
+8. Use only relation and function names exactly as `get_database_schema` returns them -- never a
+   plausible-sounding guess (a topic word like "transactions" is not a table name). If
+   `execute_read_only_sql` rejects a query, its error names what is actually available -- retry
+   once with a corrected name from that list before telling the customer you cannot answer.
 """
 
 
diff --git a/backend/app/services/chat/sql_tool_validator.py b/backend/app/services/chat/sql_tool_validator.py
index 3cfaf2b..3fdecb4 100644
--- a/backend/app/services/chat/sql_tool_validator.py
+++ b/backend/app/services/chat/sql_tool_validator.py
@@ -70,8 +70,18 @@ def validate_query(sql: str) -> ValidationResult:
         if name in cte_names:
             continue
         if name not in CURATED_VIEW_NAMES:
+            # Naming the actual allow-list here, not just rejecting, is load-bearing: the model
+            # has been observed guessing a plausible-sounding relation name (e.g. `transactions`
+            # for the topic word in its own system prompt) instead of the real view name
+            # (`v_transaction_history`) and then giving up on a bare rejection rather than
+            # retrying. Putting the correction in the same tool result removes the need for it to
+            # re-call `get_database_schema` or recall the list from earlier in the turn.
             return ValidationResult(
-                ok=False, reason=f"relation '{table.name}' is not available to this assistant"
+                ok=False,
+                reason=(
+                    f"relation '{table.name}' is not available to this assistant. "
+                    f"Available views: {', '.join(sorted(CURATED_VIEW_NAMES))}."
+                ),
             )
 
     for func in statement.find_all(exp.Func):
@@ -86,8 +96,13 @@ def validate_query(sql: str) -> ValidationResult:
             continue
         name = func.name.lower() if isinstance(func, exp.Anonymous) else func.sql_name().lower()
         if name not in _ALLOWED_FUNCTIONS:
+            # Same self-correcting-message rationale as the relation check above.
             return ValidationResult(
-                ok=False, reason=f"function '{name}' is not available to this assistant"
+                ok=False,
+                reason=(
+                    f"function '{name}' is not available to this assistant. "
+                    f"Available functions: {', '.join(sorted(_ALLOWED_FUNCTIONS))}."
+                ),
             )
 
     return ValidationResult(
diff --git a/backend/tests/unit/test_sql_tool_validator.py b/backend/tests/unit/test_sql_tool_validator.py
index a0154da..bc2366f 100644
--- a/backend/tests/unit/test_sql_tool_validator.py
+++ b/backend/tests/unit/test_sql_tool_validator.py
@@ -92,3 +92,21 @@ def test_normalized_sql_drops_comments() -> None:
     assert result.ok is True
     assert result.normalized_sql is not None
     assert "sneaky" not in result.normalized_sql
+
+
+def test_off_allow_list_relation_reason_names_the_available_views() -> None:
+    """Observed live: the model guessed `transactions` instead of `v_transaction_history` and
+    gave up on a bare rejection. The error must name the real options in the same tool result."""
+    result = validate_query("SELECT * FROM transactions")
+    assert result.ok is False
+    assert result.reason is not None
+    assert "v_transaction_history" in result.reason
+    assert "v_holdings" in result.reason
+
+
+def test_disallowed_function_reason_names_the_available_functions() -> None:
+    result = validate_query("SELECT pg_sleep(5) FROM v_holdings")
+    assert result.ok is False
+    assert result.reason is not None
+    assert "sum" in result.reason
+    assert "count" in result.reason