fix(ui-automation): Address Warden contract feedback

Preserve zero-value compatibility for gesture duration and delta
validation while keeping negative values rejected.

Remove internal runtime snapshot wording from the public swipe manifest.
Keep touch success text stable when the optional event is omitted and
simplify runtime snapshot control flow.

Co-Authored-By: Codex <noreply@openai.com>

Author: cameroncooke

manifests/tools/swipe.yaml

@@ -3,7 +3,7 @@ module: mcp/tools/ui-automation/swipe
 names:
   mcp: swipe
   cli: swipe
-description: Swipe within a UI element by withinElementRef and direction from a current rs/1 runtime snapshot.
+description: Swipe within a scrollable UI element using an element reference from the latest runtime snapshot.
 outputSchema:
   schema: xcodebuildmcp.output.ui-action-result
   version: "2"

src/mcp/tools/ui-automation/__tests__/gesture.test.ts

@@ -40,7 +40,8 @@ describe('Gesture Plugin', () => {
       expect(schemaObj.safeParse({ preset: 'scroll-up', screenWidth: 2001 }).success).toBe(false);
       expect(schemaObj.safeParse({ preset: 'scroll-up', screenHeight: 3001 }).success).toBe(false);
       expect(schemaObj.safeParse({ preset: 'scroll-up', duration: -1 }).success).toBe(false);
-      expect(schemaObj.safeParse({ preset: 'scroll-up', duration: 0 }).success).toBe(false);
+      expect(schemaObj.safeParse({ preset: 'scroll-up', duration: 0 }).success).toBe(true);
+      expect(schemaObj.safeParse({ preset: 'scroll-up', delta: 0 }).success).toBe(true);
       expect(schemaObj.safeParse({ preset: 'scroll-up', delta: 201 }).success).toBe(false);
 
       const withSimId = schemaObj.safeParse({

src/mcp/tools/ui-automation/gesture.ts

@@ -67,13 +67,13 @@ const gestureSchema = z.object({
     ),
   duration: z
     .number()
-    .positive({ message: 'Duration must be greater than 0 seconds' })
+    .min(0, { message: 'Duration must be non-negative' })
     .max(10, { message: 'Duration must be at most 10 seconds' })
     .optional()
     .describe('Duration of the gesture in seconds.'),
   delta: z
     .number()
-    .positive({ message: 'Delta must be greater than 0' })
+    .min(0, { message: 'Delta must be non-negative' })
     .max(200, { message: 'Delta must be at most 200' })
     .optional()
     .describe('Distance to move in pixels.'),

src/mcp/tools/ui-automation/shared/runtime-snapshot.ts

@@ -533,21 +533,17 @@ export function extractAccessibilityHierarchy(responseText: string): Accessibili
     throw new RuntimeSnapshotParseError(`AXe describe-ui returned invalid JSON: ${message}`);
   }
 
-  const hierarchy = (() => {
-    if (Array.isArray(parsed)) {
-      return parsed as AccessibilityNode[];
-    }
-
-    if (isRecord(parsed) && Array.isArray(parsed.elements)) {
-      return parsed.elements as AccessibilityNode[];
-    }
+  if (Array.isArray(parsed)) {
+    return parsed as AccessibilityNode[];
+  }
 
-    throw new RuntimeSnapshotParseError(
-      'AXe describe-ui did not return an accessibility element array.',
-    );
-  })();
+  if (isRecord(parsed) && Array.isArray(parsed.elements)) {
+    return parsed.elements as AccessibilityNode[];
+  }
 
-  return hierarchy;
+  throw new RuntimeSnapshotParseError(
+    'AXe describe-ui did not return an accessibility element array.',
+  );
 }
 
 export function createRuntimeSnapshotRecord(params: {
@@ -728,18 +724,21 @@ export function getRuntimeElementSwipePoints(
   const top = Math.round(frame.y + verticalInset);
   const bottom = Math.round(frame.y + frame.height - verticalInset);
 
-  const points = ((): { from: Point; to: Point } => {
-    switch (direction) {
-      case 'up':
-        return { from: { x: center.x, y: bottom }, to: { x: center.x, y: top } };
-      case 'down':
-        return { from: { x: center.x, y: top }, to: { x: center.x, y: bottom } };
-      case 'left':
-        return { from: { x: right, y: center.y }, to: { x: left, y: center.y } };
-      case 'right':
-        return { from: { x: left, y: center.y }, to: { x: right, y: center.y } };
-    }
-  })();
+  let points: { from: Point; to: Point };
+  switch (direction) {
+    case 'up':
+      points = { from: { x: center.x, y: bottom }, to: { x: center.x, y: top } };
+      break;
+    case 'down':
+      points = { from: { x: center.x, y: top }, to: { x: center.x, y: bottom } };
+      break;
+    case 'left':
+      points = { from: { x: right, y: center.y }, to: { x: left, y: center.y } };
+      break;
+    case 'right':
+      points = { from: { x: left, y: center.y }, to: { x: right, y: center.y } };
+      break;
+  }
 
   if (isDegenerateSwipe(points.from, points.to)) {
     return {

src/utils/renderers/domain-result-text.ts

@@ -2376,7 +2376,7 @@ function createSpecialCaseItems(
           break;
         }
         case 'touch':
-          successMessage = `Touch event (${result.action.event}) on elementRef ${result.action.elementRef} executed successfully.`;
+          successMessage = `Touch event (${result.action.event ?? 'touch'}) on elementRef ${result.action.elementRef} executed successfully.`;
           break;
         case 'long-press':
           successMessage = `Long press on elementRef ${result.action.elementRef} for ${result.action.durationMs}ms simulated successfully.`;