diff --git a/e2e_test/error_ui/simple/expr.slt b/e2e_test/error_ui/simple/expr.slt
index 2f330bf947f4..cabe11238088 100644
--- a/e2e_test/error_ui/simple/expr.slt
+++ b/e2e_test/error_ui/simple/expr.slt
@@ -1,3 +1,4 @@
+# Regular function
 query error
 select pow(114, 514);
 ----
@@ -9,6 +10,7 @@ Caused by these errors (recent errors listed first):
   3: Numeric out of range: overflow
 
 
+# Nullable arguments
 query error
 select array_position(array[1, null, 2, null], null, null::int);
 ----
@@ -20,6 +22,7 @@ Caused by these errors (recent errors listed first):
   3: Invalid parameter start: initial position must not be null
 
 
+# Operator
 query error
 select 11111111444 * 51444444444444444;
 ----
@@ -31,6 +34,20 @@ Caused by these errors (recent errors listed first):
   3: Numeric out of range
 
 
+# Cast
+query error
+select 'foo'::bigint;
+----
+db error: ERROR: Failed to run the query
+
+Caused by these errors (recent errors listed first):
+  1: Expr error
+  2: error while evaluating expression `str_parse(foo)`
+  3: Parse error: bigint invalid digit found in string
+
+
+# Prebuild context
+# TODO: not included in the error message
 query error
 select jsonb_path_exists('{"a":[1,2,3,4,5]}', '$.a[*] ? (@ >= $min && @ <= $max)', '"foo"');
 ----
@@ -42,6 +59,7 @@ Caused by these errors (recent errors listed first):
   3: Invalid parameter jsonpath: "vars" argument is not an object
 
 
+# Variadic arguments
 query error
 select format('%L %s', 'Hello', 'World');
 ----