Implementation for SEP-2243 Http Standardization (#1553)

Co-authored-by: Tarek Mahmoud Sayed <tarekms@microsoft.com>
Co-authored-by: Tarek Mahmoud Sayed <tarekms@ntdev.microsoft.com>
Co-authored-by: Tarek Mahmoud Sayed <10833894+tarekgh@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

tests/ModelContextProtocol.Tests/Client/McpClientToolRejectionTests.cs

@@ -0,0 +1,67 @@
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using ModelContextProtocol.Client;
+using ModelContextProtocol.Protocol;
+using ModelContextProtocol.Server;
+using System.Text.Json;
+
+namespace ModelContextProtocol.Tests.Client;
+
+public class McpClientToolRejectionTests : ClientServerTestBase
+{
+    private const string InvalidToolName = "InvalidHeaderTool";
+    private const string ValidToolName = "ValidTool";
+
+    public McpClientToolRejectionTests(ITestOutputHelper outputHelper)
+        : base(outputHelper)
+    {
+    }
+
+    protected override void ConfigureServices(ServiceCollection services, IMcpServerBuilder mcpServerBuilder)
+    {
+        // Register a valid tool.
+        mcpServerBuilder.WithTools([McpServerTool.Create(
+            (string input) => $"echo {input}",
+            new() { Name = ValidToolName })]);
+
+        // Register a tool whose InputSchema has an invalid x-mcp-header (colon in header name).
+        var invalidTool = McpServerTool.Create(
+            (string region) => $"result for {region}",
+            new() { Name = InvalidToolName });
+
+        // Manually inject an invalid x-mcp-header annotation into the schema.
+        // The header name "Invalid:Header" contains a colon, which is prohibited.
+        var schemaJson = """
+            {
+                "type": "object",
+                "properties": {
+                    "region": {
+                        "type": "string",
+                        "x-mcp-header": "Invalid:Header"
+                    }
+                }
+            }
+            """;
+        invalidTool.ProtocolTool.InputSchema = JsonDocument.Parse(schemaJson).RootElement.Clone();
+
+        mcpServerBuilder.WithTools([invalidTool]);
+    }
+
+    [Fact]
+    public async Task ListToolsAsync_ExcludesToolWithInvalidXMcpHeader_AndLogsWarning()
+    {
+        // Act
+        await using var client = await CreateMcpClientForServer();
+        var tools = await client.ListToolsAsync(cancellationToken: TestContext.Current.CancellationToken);
+
+        // Assert: the valid tool is returned, the invalid one is excluded.
+        Assert.Contains(tools, t => t.Name == ValidToolName);
+        Assert.DoesNotContain(tools, t => t.Name == InvalidToolName);
+
+        // Assert: a warning was logged about the rejected tool.
+        Assert.Contains(MockLoggerProvider.LogMessages, log =>
+            log.LogLevel == LogLevel.Warning &&
+            log.Message.Contains(InvalidToolName) &&
+            log.Message.Contains("excluded"));
+    }
+}