From 42c2533747619818d7ac8ebd780cf0f56c2873dd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignacy=20=C5=81=C4=85tka?= <latkaignacy@gmail.com>
Date: Mon, 12 Oct 2026 14:28:50 +0200
Subject: [PATCH 1/2] fix(screenshot-diff): reject string values for
 captureBaseline/captureCurrent

z.coerce.boolean() is JS truthiness, so the string "false" parsed to true
and a caller that declined a live capture got one. Use z.boolean() like
every other boolean param in the catalogue.

Closes #811
---
 packages/tool-server/src/tools/screenshot-diff/index.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/tool-server/src/tools/screenshot-diff/index.ts b/packages/tool-server/src/tools/screenshot-diff/index.ts
index c42e34ea0e..c701cb6664 100644
--- a/packages/tool-server/src/tools/screenshot-diff/index.ts
+++ b/packages/tool-server/src/tools/screenshot-diff/index.ts
@@ -42,13 +42,13 @@ const zodSchema = z
       .string()
       .min(1)
       .describe("Target device id from `list-devices` (iOS UDID or Android serial)."),
-    captureBaseline: z.coerce
+    captureBaseline: z
       .boolean()
       .optional()
       .describe(
         "Capture the baseline screenshot live at full resolution before diffing. Cannot be combined with captureCurrent."
       ),
-    captureCurrent: z.coerce
+    captureCurrent: z
       .boolean()
       .optional()
       .describe(

From 1846c55e5dd42992df8c5b289871873b8bcf1886 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ignacy=20=C5=81=C4=85tka?= <latkaignacy@gmail.com>
Date: Mon, 12 Oct 2026 20:37:33 +0200
Subject: [PATCH 2/2] test(screenshot-diff): reject a string capture flag

---
 .../tool-server/test/screenshot-diff-tool.test.ts     | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/packages/tool-server/test/screenshot-diff-tool.test.ts b/packages/tool-server/test/screenshot-diff-tool.test.ts
index 6c2741ca94..01657cc81c 100644
--- a/packages/tool-server/test/screenshot-diff-tool.test.ts
+++ b/packages/tool-server/test/screenshot-diff-tool.test.ts
@@ -44,6 +44,17 @@ describe("screenshotDiffTool", () => {
     expect(result.success).toBe(false);
   });
 
+  it.each(["captureBaseline", "captureCurrent"])("rejects a string %s", (flag) => {
+    const result = screenshotDiffTool.zodSchema!.safeParse({
+      baselinePath: "/tmp/baseline.png",
+      currentPath: "/tmp/current.png",
+      udid: "ABC",
+      [flag]: "false",
+    });
+
+    expect(result.error?.issues).toMatchObject([{ code: "invalid_type", path: [flag] }]);
+  });
+
   it("requires udid and only declares the simulator-server service for live captures", () => {
     expect(
       screenshotDiffTool.zodSchema!.safeParse({