diff --git a/package.json b/package.json
index d848a81bf8c..62e4ac826fa 100644
--- a/package.json
+++ b/package.json
@@ -79,12 +79,12 @@
     "json": "^11.0.0",
     "lodash": "^4.17.21",
     "memfs": "^4.17.2",
+    "mnemonist": "^0.40.3",
     "mock-fs": "^5.5.0",
     "prettier": "^3.5.3",
     "react-devtools-core": "^4.28.5",
     "typescript-eslint": "^8.30.1",
     "vitest": "^3.2.4",
-    "yargs": "^17.7.2",
-    "mnemonist": "^0.40.3"
+    "yargs": "^17.7.2"
   }
 }
diff --git a/packages/cli/src/ui/commands/restoreCommand.test.ts b/packages/cli/src/ui/commands/restoreCommand.test.ts
index 23f7149918a..cf8e7baca55 100644
--- a/packages/cli/src/ui/commands/restoreCommand.test.ts
+++ b/packages/cli/src/ui/commands/restoreCommand.test.ts
@@ -213,7 +213,7 @@ describe('restoreCommand', () => {
       type: 'message',
       messageType: 'error',
       // A more specific error message would be ideal, but for now, we can assert the current behavior.
-      content: expect.stringContaining('Could not read restorable tool calls.'),
+      content: 'Checkpoint file is missing toolCall data.',
     });
   });
 
diff --git a/packages/cli/src/ui/commands/restoreCommand.ts b/packages/cli/src/ui/commands/restoreCommand.ts
index 84259288dcc..f89fb2a3aab 100644
--- a/packages/cli/src/ui/commands/restoreCommand.ts
+++ b/packages/cli/src/ui/commands/restoreCommand.ts
@@ -13,6 +13,7 @@ import {
   CommandKind,
 } from './types.js';
 import { Config } from '@google/gemini-cli-core';
+import { z } from 'zod';
 
 async function restoreAction(
   context: CommandContext,
@@ -76,7 +77,27 @@ async function restoreAction(
 
     const filePath = path.join(checkpointDir, selectedFile);
     const data = await fs.readFile(filePath, 'utf-8');
-    const toolCallData = JSON.parse(data);
+    const parsedData = JSON.parse(data);
+
+    const toolCallDataSchema = z.object({
+      history: z.array(z.any()).optional(),
+      clientHistory: z.array(z.any()).optional(),
+      commitHash: z.string().optional(),
+      toolCall: z.object({
+        name: z.string(),
+        args: z.any(),
+      }).optional(),
+    });
+
+    const toolCallData = toolCallDataSchema.parse(parsedData);
+
+    if (!toolCallData.toolCall) {
+      return {
+        type: 'message',
+        messageType: 'error',
+        content: 'Checkpoint file is missing toolCall data.',
+      };
+    }
 
     if (toolCallData.history) {
       if (!loadHistory) {
diff --git a/packages/core/src/utils/errors.test.ts b/packages/core/src/utils/errors.test.ts
index ec42a3f954f..67362d48cc6 100644
--- a/packages/core/src/utils/errors.test.ts
+++ b/packages/core/src/utils/errors.test.ts
@@ -4,7 +4,7 @@ import {
   BadRequestError,
   UnauthorizedError,
   ForbiddenError,
-} from './errors';
+} from './errors.js';
 
 describe('toFriendlyError', () => {
   it('should return the original error if it is not an object', () => {