diff --git a/components/optimization_guide/proto/features/common_quality_data.proto b/components/optimization_guide/proto/features/common_quality_data.proto
index 18074697..fe23cb03 100644
--- a/components/optimization_guide/proto/features/common_quality_data.proto
+++ b/components/optimization_guide/proto/features/common_quality_data.proto
@@ -243,7 +243,7 @@
   ContentAttributes content_attributes = 2;
 }
 
-// Next ID: 24
+// Next ID: 25
 message ContentAttributes {
   oneof content_data {
     // Only set if attribute_type is CONTENT_ATTRIBUTE_TEXT.
@@ -255,6 +255,9 @@
     // Only set if attribute_type is CONTENT_ATTRIBUTE_SVG.
     SVGData svg_data = 23;
 
+    // Only set if attribute_type is CONTENT_ATTRIBUTE_CANVAS.
+    CanvasData canvas_data = 24;
+
     // Only set if attribute_type is CONTENT_ATTRIBUTE_ANCHOR.
     AnchorData anchor_data = 14;
 
@@ -441,6 +444,12 @@
   string inner_text = 1;
 }
 
+message CanvasData {
+  int32 layout_width = 1;
+
+  int32 layout_height = 2;
+}
+
 message AnchorData {
   string url = 1;
 
@@ -1614,7 +1623,7 @@
 // When adding new types, please also update AIPageContentAttributeType in
 // third_party/blink/public/mojom/content_extraction/ai_page_content.mojom.
 // See crrev.com/c/6072788 for an example.
-// Next ID: 26;
+// Next ID: 27;
 enum ContentAttributeType {
   // Unknown is not a valid attribute type and should never be used by the
   // client. You can consider discarding ContentNodes with this attribute type.
@@ -1640,6 +1649,8 @@
 
   CONTENT_ATTRIBUTE_SVG = 25;
 
+  CONTENT_ATTRIBUTE_CANVAS = 26;
+
   // Structured chunks.
   CONTENT_ATTRIBUTE_ORDERED_LIST = 6;
 
diff --git a/components/optimization_guide/proto/features/writing_assistance_api.proto b/components/optimization_guide/proto/features/writing_assistance_api.proto
index 41cfeec..5876ac5 100644
--- a/components/optimization_guide/proto/features/writing_assistance_api.proto
+++ b/components/optimization_guide/proto/features/writing_assistance_api.proto
@@ -35,6 +35,8 @@
   string rewrite_text = 3;
 
   string shared_context = 4;
+
+  string instructions = 5;
 }
 
 message WritingAssistanceApiOptions {