From 80207221409d98dfd022d8a4f3b75adbc6f7c812 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 19 Feb 2026 13:43:07 +0000
Subject: [PATCH 1/2] Initial plan


From 3395643c6174a435619b7e7c71279d3797ac147f Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 19 Feb 2026 13:57:42 +0000
Subject: [PATCH 2/2] Add missing [Experimental] attributes for MCP tasks
 properties

Add [Experimental(Experimentals.Tasks_DiagnosticId, UrlFormat = Experimentals.Tasks_Url)]
to three task-related properties that were accidentally missing it:
- CallToolResult.Task (McpTask?)
- ClientCapabilities.Tasks (McpTasksCapability?)
- ServerCapabilities.Tasks (McpTasksCapability?)

Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>
---
 src/ModelContextProtocol.Core/Protocol/CallToolResult.cs     | 2 ++
 src/ModelContextProtocol.Core/Protocol/ClientCapabilities.cs | 2 ++
 src/ModelContextProtocol.Core/Protocol/ServerCapabilities.cs | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/src/ModelContextProtocol.Core/Protocol/CallToolResult.cs b/src/ModelContextProtocol.Core/Protocol/CallToolResult.cs
index e760d2f4f..5902dbff2 100644
--- a/src/ModelContextProtocol.Core/Protocol/CallToolResult.cs
+++ b/src/ModelContextProtocol.Core/Protocol/CallToolResult.cs
@@ -1,3 +1,4 @@
+using System.Diagnostics.CodeAnalysis;
 using System.Text.Json.Nodes;
 using System.Text.Json.Serialization;
 
@@ -72,6 +73,7 @@ public sealed class CallToolResult : Result
     /// (<see cref="Content"/>, <see cref="StructuredContent"/>, <see cref="IsError"/>) may not be populated.
     /// The actual tool result can be retrieved later via <c>tasks/result</c>.
     /// </remarks>
+    [Experimental(Experimentals.Tasks_DiagnosticId, UrlFormat = Experimentals.Tasks_Url)]
     [JsonPropertyName("task")]
     public McpTask? Task { get; set; }
 }
diff --git a/src/ModelContextProtocol.Core/Protocol/ClientCapabilities.cs b/src/ModelContextProtocol.Core/Protocol/ClientCapabilities.cs
index cb85ef5e3..7f6729783 100644
--- a/src/ModelContextProtocol.Core/Protocol/ClientCapabilities.cs
+++ b/src/ModelContextProtocol.Core/Protocol/ClientCapabilities.cs
@@ -1,4 +1,5 @@
 using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
 using System.Text.Json.Serialization;
 using ModelContextProtocol.Client;
 using ModelContextProtocol.Server;
@@ -80,6 +81,7 @@ public sealed class ClientCapabilities
     /// See <see cref="McpTasksCapability"/> for details on configuring which operations support tasks.
     /// </para>
     /// </remarks>
+    [Experimental(Experimentals.Tasks_DiagnosticId, UrlFormat = Experimentals.Tasks_Url)]
     [JsonPropertyName("tasks")]
     public McpTasksCapability? Tasks { get; set; }
 }
diff --git a/src/ModelContextProtocol.Core/Protocol/ServerCapabilities.cs b/src/ModelContextProtocol.Core/Protocol/ServerCapabilities.cs
index 499819662..8b5bd6792 100644
--- a/src/ModelContextProtocol.Core/Protocol/ServerCapabilities.cs
+++ b/src/ModelContextProtocol.Core/Protocol/ServerCapabilities.cs
@@ -1,4 +1,5 @@
 using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
 using System.Text.Json.Serialization;
 using ModelContextProtocol.Server;
 
@@ -79,6 +80,7 @@ public sealed class ServerCapabilities
     /// See <see cref="McpTasksCapability"/> for details on configuring which operations support tasks.
     /// </para>
     /// </remarks>
+    [Experimental(Experimentals.Tasks_DiagnosticId, UrlFormat = Experimentals.Tasks_Url)]
     [JsonPropertyName("tasks")]
     public McpTasksCapability? Tasks { get; set; }
 }