feat: optimize vision tools and image handling

- Add model-aware vision tool loading based on supports_vision flag
- Move view_image_tool from config to builtin tools for dynamic inclusion
- Add timeout to image search to prevent hanging requests
- Optimize image search results format using thumbnails
- Add image validation for reference images in generation
- Improve error handling with detailed messages

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

skills/public/image-generation/scripts/generate.py

@@ -2,6 +2,29 @@ import base64
 import os
 
 import requests
+from PIL import Image
+
+
+def validate_image(image_path: str) -> bool:
+    """
+    Validate if an image file can be opened and is not corrupted.
+    
+    Args:
+        image_path: Path to the image file
+        
+    Returns:
+        True if the image is valid and can be opened, False otherwise
+    """
+    try:
+        with Image.open(image_path) as img:
+            img.verify()  # Verify that it's a valid image
+        # Re-open to check if it can be fully loaded (verify() may not catch all issues)
+        with Image.open(image_path) as img:
+            img.load()  # Force load the image data
+        return True
+    except Exception as e:
+        print(f"Warning: Image '{image_path}' is invalid or corrupted: {e}")
+        return False
 
 
 def generate_image(
@@ -14,7 +37,19 @@ def generate_image(
         prompt = f.read()
     parts = []
     i = 0
-    for reference_image in reference_images:
+    
+    # Filter out invalid reference images
+    valid_reference_images = []
+    for ref_img in reference_images:
+        if validate_image(ref_img):
+            valid_reference_images.append(ref_img)
+        else:
+            print(f"Skipping invalid reference image: {ref_img}")
+    
+    if len(valid_reference_images) < len(reference_images):
+        print(f"Note: {len(reference_images) - len(valid_reference_images)} reference image(s) were skipped due to validation failure.")
+    
+    for reference_image in valid_reference_images:
         i += 1
         with open(reference_image, "rb") as f:
             image_b64 = base64.b64encode(f.read()).decode("utf-8")
@@ -41,6 +76,7 @@ def generate_image(
             "contents": [{"parts": [*parts, {"text": prompt}]}],
         },
     )
+    response.raise_for_status()
     json = response.json()
     parts: list[dict] = json["candidates"][0]["content"]["parts"]
     image_parts = [part for part in parts if part.get("inlineData", False)]
@@ -92,5 +128,5 @@ if __name__ == "__main__":
                 args.aspect_ratio,
             )
         )
-    except Exception:
-        print("Error while generating image.")
+    except Exception as e:
+        print(f"Error while generating image: {e}")