diff --git a/packages/pen-mcp/src/__tests__/element-tools-contract.test.ts b/packages/pen-mcp/src/__tests__/element-tools-contract.test.ts
index ea44388e1..ed53c7800 100644
--- a/packages/pen-mcp/src/__tests__/element-tools-contract.test.ts
+++ b/packages/pen-mcp/src/__tests__/element-tools-contract.test.ts
@@ -152,4 +152,51 @@ describe('element tools — silent no-op guards (P0.1 + post-insert check)', ()
     const after = await readFile(fp, 'utf-8');
     expect(after).toBe(before);
   });
+
+  it('throws when DSL-resolved parent_id collides with a different node (wrong-parent insert)', async () => {
+    // Seed the document with TWO frames:
+    //   - intended parent, id = `A"B` (3 chars: A, ", B) — the user's target
+    //   - decoy parent,    id = `A\"B` (4 chars: A, \, ", B) — happens to
+    //     be what batch_design's resolveRef produces after quote-strip on
+    //     our JSON.stringify output for 'A"B'
+    // Expected: ensureParentExists finds the intended parent (raw string
+    // match ✓), but insertNodeInTree resolves to the decoy (literal match
+    // on the 4-char id). Without parent-location verification, the node
+    // would silently land under the wrong parent.
+    const fp = join(TMP, 'quoted-parent.op');
+    await writeFile(
+      fp,
+      JSON.stringify({
+        version: '1.0.0',
+        children: [
+          {
+            id: 'A"B',
+            type: 'frame',
+            name: 'Intended Parent',
+            width: 1200,
+            height: 0,
+            layout: 'vertical',
+            children: [],
+          },
+          {
+            id: 'A\\"B',
+            type: 'frame',
+            name: 'Decoy Parent',
+            width: 1200,
+            height: 0,
+            layout: 'vertical',
+            children: [],
+          },
+        ],
+      }),
+      'utf-8',
+    );
+    await expect(
+      handleAddBottomNavV0({
+        filePath: fp,
+        parent_id: 'A"B',
+        items: [{ title: 'Home', icon: 'home' }],
+      }),
+    ).rejects.toThrow(/wrong parent|not present/);
+  });
 });
diff --git a/packages/pen-mcp/src/tools/element-tool-helpers.ts b/packages/pen-mcp/src/tools/element-tool-helpers.ts
index ab8314f93..6c8c2e3fa 100644
--- a/packages/pen-mcp/src/tools/element-tool-helpers.ts
+++ b/packages/pen-mcp/src/tools/element-tool-helpers.ts
@@ -1,5 +1,5 @@
 import { openDocument, resolveDocPath } from '../document-manager';
-import { findNodeInTree, getDocChildren } from '../utils/node-operations';
+import { findNodeInTree, findParentInTree, getDocChildren } from '../utils/node-operations';
 import { generateId } from '../utils/id';
 import { handleBatchDesign } from './batch-design';
 
@@ -147,5 +147,25 @@ export async function insertElementTree(args: {
         `parent_id=${JSON.stringify(args.parent_id)}, pageId=${JSON.stringify(args.pageId)}.`,
     );
   }
+  // Parent-location verification: node exists in tree but may have landed
+  // under the wrong parent. Can happen if batch_design's resolveRef
+  // quote-strip produces a literal that matches a DIFFERENT node than the
+  // one pre-check validated. Example: doc has both `A"B` (user intent)
+  // AND `A\"B` (literal 4-char id with backslash); after JSON.stringify
+  // + quote-strip, parser resolves to `A\"B` and inserts under it.
+  // ensureParentExists and the "landed in tree" check both pass, but
+  // the insert went to the wrong place.
+  if (args.parent_id) {
+    const actualParent = findParentInTree(postChildren, insertedId);
+    const actualParentId = actualParent?.id ?? null;
+    if (actualParentId !== args.parent_id) {
+      throw new Error(
+        `Element tool insert landed under the wrong parent: expected ` +
+          `${JSON.stringify(args.parent_id)}, got ${JSON.stringify(actualParentId ?? 'root')}. ` +
+          `This is typically a DSL-parser escape mismatch where the resolved parent id ` +
+          `happens to collide with a different node's literal id.`,
+      );
+    }
+  }
   return result;
 }