diff --git a/src/Integrations/Divi/Design/DiviColorsSetAbility.php b/src/Integrations/Divi/Design/DiviColorsSetAbility.php
index 0baec8b..753df7d 100644
--- a/src/Integrations/Divi/Design/DiviColorsSetAbility.php
+++ b/src/Integrations/Divi/Design/DiviColorsSetAbility.php
@@ -99,6 +99,7 @@ final class DiviColorsSetAbility implements Ability, RequiresDiviFeatures
                     'maxItems' => self::MAX_ITEMS,
                     'items' => [
                         'type' => 'object',
+                        'additionalProperties' => false,
                         'properties' => [
                             'id' => [
                                 'type' => 'string',
@@ -226,6 +227,13 @@ final class DiviColorsSetAbility implements Ability, RequiresDiviFeatures
     private function apply(ColorBook $book, array $item, string $field, array &$errors): ColorBook
     {
         $known = count($errors);
+        ItemKeys::refuseUnknown(
+            $item,
+            ['id', 'label', 'color', 'relative', 'folder', 'status'],
+            $field,
+            $errors,
+            'Farben werden nicht gelöscht, nur deaktiviert (status: inactive)'
+        );
         $id = array_key_exists('id', $item) ? self::existing($book, $item['id'], $field . '.id', $errors) : null;
         if (count($errors) > $known) {
             return $book;
diff --git a/src/Integrations/Divi/Design/DiviVariablesSetAbility.php b/src/Integrations/Divi/Design/DiviVariablesSetAbility.php
index 0ed7d36..eab2c51 100644
--- a/src/Integrations/Divi/Design/DiviVariablesSetAbility.php
+++ b/src/Integrations/Divi/Design/DiviVariablesSetAbility.php
@@ -87,6 +87,7 @@ final class DiviVariablesSetAbility implements Ability, RequiresDiviFeatures
                     'maxItems' => self::MAX_ITEMS,
                     'items' => [
                         'type' => 'object',
+                        'additionalProperties' => false,
                         'properties' => [
                             'id' => ['type' => 'string', 'description' => 'Vorhandene Variable: ID oder Name.'],
                             'type' => [
@@ -201,6 +202,13 @@ final class DiviVariablesSetAbility implements Ability, RequiresDiviFeatures
     private function apply(VariableBook $book, array $item, string $field, array &$errors): VariableBook
     {
         $known = count($errors);
+        ItemKeys::refuseUnknown(
+            $item,
+            ['id', 'type', 'label', 'value', 'status'],
+            $field,
+            $errors,
+            'Variablen werden nicht gelöscht, nur archiviert (status: archived)'
+        );
         $named = array_key_exists('id', $item);
         $found = $named ? self::existing($book, $item, $field, $errors) : null;
         $type = $found['type'] ?? ($named ? null : self::newType($item, $field, $errors));
diff --git a/src/Integrations/Divi/Design/ItemKeys.php b/src/Integrations/Divi/Design/ItemKeys.php
new file mode 100644
index 0000000..1facc73
--- /dev/null
+++ b/src/Integrations/Divi/Design/ItemKeys.php
@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Integrations\Divi\Design;
+
+defined('ABSPATH') || exit;
+
+/** Refuses item keys a tool does not know, so "delete" or a typo is never taken for a successful no-op. */
+final class ItemKeys
+{
+    /**
+     * @param array<array-key, mixed> $item
+     * @param list<string>            $allowed
+     * @param array<string, string>   $errors   gets one entry per unknown key (field.key)
+     */
+    public static function refuseUnknown(array $item, array $allowed, string $field, array &$errors, string $deleteHint): void
+    {
+        foreach (array_diff(array_map('strval', array_keys($item)), $allowed) as $key) {
+            $errors[$field . '.' . $key] = $key === 'delete' ? 'unbekanntes Feld; ' . $deleteHint : 'unbekanntes Feld';
+        }
+    }
+}
diff --git a/tests/Unit/Integrations/Divi/Design/DiviColorsSetAbilityTest.php b/tests/Unit/Integrations/Divi/Design/DiviColorsSetAbilityTest.php
index 9e3e1f5..1f53657 100644
--- a/tests/Unit/Integrations/Divi/Design/DiviColorsSetAbilityTest.php
+++ b/tests/Unit/Integrations/Divi/Design/DiviColorsSetAbilityTest.php
@@ -276,6 +276,23 @@ final class DiviColorsSetAbilityTest extends TestCase
         self::assertSame([], $this->saves);
     }
 
+    public function testUnknownItemKeysAreRefusedAndCollectedWithOtherErrors(): void
+    {
+        $error = $this->ability()->execute(['items' => [
+            ['id' => 'gcid-holz000001', 'delete' => true],
+            ['id' => 'gcid-holz000001', 'stauts' => 'inactive'],
+            ['id' => 'Fehlt', 'color' => '#ffffff'],
+        ]]);
+
+        self::assertToolError($error, 'validation_failed');
+        $fields = self::errorFields($error);
+        self::assertSame(['items[0].delete', 'items[1].stauts', 'items[2].id'], array_keys($fields));
+        self::assertStringContainsString('inactive', $fields['items[0].delete']);
+        self::assertSame('unbekanntes Feld', $fields['items[1].stauts']);
+        self::assertSame([], $this->saves);
+        self::assertFalse($this->ability()->inputSchema()['properties']['items']['items']['additionalProperties']);
+    }
+
     public function testAFailedWriteIsRolledBack(): void
     {
         $calls = [];
diff --git a/tests/Unit/Integrations/Divi/Design/DiviVariablesSetAbilityTest.php b/tests/Unit/Integrations/Divi/Design/DiviVariablesSetAbilityTest.php
index f2494a7..6bbf9d0 100644
--- a/tests/Unit/Integrations/Divi/Design/DiviVariablesSetAbilityTest.php
+++ b/tests/Unit/Integrations/Divi/Design/DiviVariablesSetAbilityTest.php
@@ -275,6 +275,24 @@ final class DiviVariablesSetAbilityTest extends TestCase
         self::assertSame([], $this->saves);
     }
 
+    /** Ruling V1: "delete" (or a typo) must not look like a successful no-op. */
+    public function testUnknownItemKeysAreRefusedAndCollectedWithOtherErrors(): void
+    {
+        $error = $this->ability()->execute(['items' => [
+            ['id' => 'Slogan', 'delete' => true],
+            ['id' => 'Slogan', 'stauts' => 'archived'],
+            ['id' => 'Fehlt', 'value' => '1px'],
+        ]]);
+
+        self::assertToolError($error, 'validation_failed');
+        $fields = self::errorFields($error);
+        self::assertSame(['items[0].delete', 'items[1].stauts', 'items[2].id'], array_keys($fields));
+        self::assertStringContainsString('archiviert', $fields['items[0].delete']);
+        self::assertSame('unbekanntes Feld', $fields['items[1].stauts']);
+        self::assertSame([], $this->saves);
+        self::assertFalse($this->ability()->inputSchema()['properties']['items']['items']['additionalProperties']);
+    }
+
     /** Divi silently drops variables with an empty label or the label "0" (sanitize_global_variables_data). */
     public function testEmptyAndZeroLabelsAreRefused(): void
     {