Implementing annotated tool call

Author: aaronpowell

samples/EverythingServer/Tools/AnnotatedMessageTool.cs

@@ -1,4 +1,5 @@
-using ModelContextProtocol.Server;
+using ModelContextProtocol.Protocol.Types;
+using ModelContextProtocol.Server;
 using System.ComponentModel;
 
 namespace EverythingServer.Tools;
@@ -14,8 +15,42 @@ public enum MessageType
     }
 
     [McpServerTool(Name = "annotatedMessage"), Description("Generates an annotated message")]
-    public static IEnumerable<string> AnnotatedMessage(MessageType messageType, bool includeImage = true)
+    public static IEnumerable<Content> AnnotatedMessage(MessageType messageType, bool includeImage = true)
     {
-        throw new NotSupportedException("Unable to write annotations to the output.");
+        List<Content> contents = messageType switch
+        {
+            MessageType.Error => [new()
+            {
+                Type = "text",
+                Text = "Error: Operation failed",
+                Annotations = new() { Audience = [Role.User, Role.Assistant], Priority = 1.0f }
+            }],
+            MessageType.Success => [new()
+            {
+                Type = "text",
+                Text = "Operation completed successfully",
+                Annotations = new() { Audience = [Role.User], Priority = 0.7f }
+            }],
+            MessageType.Debug => [new()
+            {
+                Type = "text",
+                Text = "Debug: Cache hit ratio 0.95, latency 150ms",
+                Annotations = new() { Audience = [Role.Assistant], Priority = 0.3f }
+            }],
+            _ => throw new ArgumentOutOfRangeException(nameof(messageType), messageType, null)
+        };
+
+        if (includeImage)
+        {
+            contents.Add(new()
+            {
+                Type = "image",
+                Data = TinyImageTool.MCP_TINY_IMAGE.Split(",").Last(),
+                MimeType = "image/png",
+                Annotations = new() { Audience = [Role.User], Priority = 0.5f }
+            });
+        }
+
+        return contents;
     }
 }