[mcp] Removed @mcpTool directive (#8944)

Author: glen-84

src/HotChocolate/Adapters/src/Adapters.Mcp.Core/Directives/McpToolDirective.cs

@@ -21,9 +21,6 @@
   <data name="CallToolHandler_ToolNotFound" xml:space="preserve">
     <value>The tool '{0}' was not found.</value>
   </data>
-  <data name="McpToolDirectiveParser_ArgumentNotSupportedOnMcpToolDirective" xml:space="preserve">
-    <value>The argument `{0}` is not supported on @mcpTool.</value>
-  </data>
   <data name="OpenAiComponent_ToolInvokedStatusTextCannotExceed64Characters" xml:space="preserve">
     <value>ToolInvokedStatusText cannot exceed 64 characters.</value>
   </data>

src/HotChocolate/Adapters/src/Adapters.Mcp.Core/Directives/McpToolDirectiveParser.cs

@@ -1,10 +1,8 @@
 using System.Security.Cryptography;
 using System.Text;
 using CaseConverter;
-using HotChocolate.Adapters.Mcp.Extensions;
 using HotChocolate.Language;
 using static HotChocolate.Adapters.Mcp.Properties.McpAdapterResources;
-using static HotChocolate.Adapters.Mcp.WellKnownDirectiveNames;
 
 namespace HotChocolate.Adapters.Mcp.Storage;
 
@@ -24,16 +22,16 @@ public sealed class OperationToolDefinition
     /// The name of the MCP tool.
     /// </param>
     /// <param name="title">
-    /// Optional tool title. Overrides directive metadata if provided.
+    /// Optional tool title.
     /// </param>
     /// <param name="destructiveHint">
-    /// Optional destructive operation hint. Overrides directive metadata if provided.
+    /// Optional destructive operation hint.
     /// </param>
     /// <param name="idempotentHint">
-    /// Optional idempotent operation hint. Overrides directive metadata if provided.
+    /// Optional idempotent operation hint.
     /// </param>
     /// <param name="openWorldHint">
-    /// Optional open-world assumption hint. Overrides directive metadata if provided.
+    /// Optional open-world assumption hint.
     /// </param>
     /// <exception cref="ArgumentException">
     /// Thrown when document doesn't contain exactly one operation.
@@ -69,48 +67,12 @@ public OperationToolDefinition(
                 nameof(document));
         }
 
-        // If we find a tool directive, parse it and remove it from the document.
-        // The tool directive is metadata only and doesn't exist in the target schema.
-        // Removing it prevents execution errors when the operation is executed.
-        var toolDirective = operation.GetMcpToolDirective();
-        if (toolDirective is not null)
-        {
-            var tempDirectives = operation.Directives.ToList();
-            foreach (var directive in operation.Directives)
-            {
-                if (directive.Name.Value.Equals(McpTool))
-                {
-                    tempDirectives.Remove(directive);
-                }
-            }
-
-            IReadOnlyList<DirectiveNode> cleanedDirectives;
-            if (tempDirectives.Count == 0)
-            {
-                cleanedDirectives = [];
-            }
-            else
-            {
-                tempDirectives.Capacity = tempDirectives.Count;
-                cleanedDirectives = tempDirectives;
-            }
-
-            var cleanedOperation = operation.WithDirectives(cleanedDirectives);
-            var cleanedDefinitions = document.Definitions.ToList();
-            cleanedDefinitions.Remove(operation);
-            cleanedDefinitions.Add(cleanedOperation);
-            cleanedDefinitions.Capacity = cleanedDefinitions.Count;
-            document = document.WithDefinitions(cleanedDefinitions);
-        }
-
         Name = name ?? operation.Name?.Value.ToSnakeCase()!;
         Document = document;
-
-        // Explicit parameters take precedence over directive metadata.
-        Title = title ?? toolDirective?.Title;
-        DestructiveHint = destructiveHint ?? toolDirective?.DestructiveHint;
-        IdempotentHint = idempotentHint ?? toolDirective?.IdempotentHint;
-        OpenWorldHint = openWorldHint ?? toolDirective?.OpenWorldHint;
+        Title = title;
+        DestructiveHint = destructiveHint;
+        IdempotentHint = idempotentHint;
+        OpenWorldHint = openWorldHint;
     }
 
     /// <summary>

src/HotChocolate/Adapters/src/Adapters.Mcp.Core/Extensions/OperationDefinitionNodeExtensions.cs

@@ -3,7 +3,6 @@ namespace HotChocolate.Adapters.Mcp;
 internal static class WellKnownDirectiveNames
 {
     public const string Include = "include";
-    public const string McpTool = "mcpTool";
     public const string McpToolAnnotations = "mcpToolAnnotations";
     public const string Skip = "skip";
 }

src/HotChocolate/Adapters/src/Adapters.Mcp.Core/Properties/McpAdapterResources.Designer.cs

@@ -183,12 +183,13 @@ await storage.AddOrUpdateToolAsync(
             new OperationToolDefinition(
                 Utf8GraphQLParser.Parse(
                     """
-                    query GetBooks @mcpTool(title: "Custom Title") {
+                    query GetBooks {
                         books {
                             title
                         }
                     }
-                    """)));
+                    """),
+                title: "Custom Title"));
         var server = await CreateTestServerAsync(storage);
         var mcpClient = await CreateMcpClientAsync(server.CreateClient());
 
@@ -200,18 +201,21 @@ query GetBooks @mcpTool(title: "Custom Title") {
     }
 
     [Fact]
-    public async Task ListTools_SetAnnotationsInDocument_ReturnsExpectedResult()
+    public async Task ListTools_SetAnnotations_ReturnsExpectedResult()
     {
         // arrange
         var storage = new TestOperationToolStorage();
         await storage.AddOrUpdateToolAsync(
             new OperationToolDefinition(
                 Utf8GraphQLParser.Parse(
                     """
-                    mutation AddBook @mcpTool(destructiveHint: false, idempotentHint: true, openWorldHint: false) {
+                    mutation AddBook {
                         addBook { title }
                     }
-                    """)));
+                    """),
+                destructiveHint: false,
+                idempotentHint: true,
+                openWorldHint: false));
         var server = await CreateTestServerAsync(storage);
         var mcpClient = await CreateMcpClientAsync(server.CreateClient());
 
@@ -288,15 +292,17 @@ public async Task ListTools_UpdateToolsInvalidDocument_ReturnsExpectedResult()
         var storage = new TestOperationToolStorage();
         await storage.AddOrUpdateToolAsync(
             new OperationToolDefinition(
-                Utf8GraphQLParser.Parse("""query Tool @mcpTool(title: "BEFORE") { books { title } }""")));
+                Utf8GraphQLParser.Parse("query Tool { books { title } }"),
+                title: "BEFORE"));
         var listener = new TestMcpDiagnosticEventListener();
         var server = await CreateTestServerAsync(storage, diagnosticEventListener: listener);
         var mcpClient = await CreateMcpClientAsync(server.CreateClient());
 
         // act
         await storage.AddOrUpdateToolAsync(
             new OperationToolDefinition(
-                Utf8GraphQLParser.Parse("""query Tool @mcpTool(title: "AFTER") { doesNotExist1, doesNotExist2 }""")));
+                Utf8GraphQLParser.Parse("query Tool { doesNotExist1, doesNotExist2 }"),
+                title: "AFTER"));
         await Task.Delay(500); // Wait for the observer buffer to flush.
         var result = await mcpClient.ListToolsAsync();
 

src/HotChocolate/Adapters/src/Adapters.Mcp.Core/Properties/McpAdapterResources.resx

@@ -155,13 +155,13 @@ public void CreateTool_SetTitle_ReturnsTool()
         var schema = CreateSchema();
         var document = Utf8GraphQLParser.Parse(
             """
-            query GetBooks @mcpTool(title: "Custom Title") {
+            query GetBooks {
                 books {
                     title
                 }
             }
             """);
-        var toolDefinition = new OperationToolDefinition(document);
+        var toolDefinition = new OperationToolDefinition(document, title: "Custom Title");
 
         // act
         var tool = new OperationToolFactory(schema).CreateTool(toolDefinition);
@@ -177,14 +177,18 @@ public void CreateTool_SetAnnotations_ReturnsTool()
         var schema = CreateSchema();
         var document = Utf8GraphQLParser.Parse(
             """
-            mutation AddBook
-                @mcpTool(destructiveHint: false, idempotentHint: true, openWorldHint: false) {
+            mutation AddBook {
                 addBook {
                     title
                 }
             }
             """);
-        var toolDefinition = new OperationToolDefinition(document);
+        var toolDefinition =
+            new OperationToolDefinition(
+                document,
+                destructiveHint: false,
+                idempotentHint: true,
+                openWorldHint: false);
 
         // act
         var tool = new OperationToolFactory(schema).CreateTool(toolDefinition);