Log tool call name on success, not just failure

src/ModelContextProtocol.Core/Server/McpServerImpl.cs

@@ -392,7 +392,17 @@ await originalListResourceTemplatesHandler(request, cancellationToken).Configure
                     }
                 }
 
-                return await handler(request, cancellationToken).ConfigureAwait(false);
+                try
+                {
+                    var result = await handler(request, cancellationToken).ConfigureAwait(false);
+                    ReadResourceCompleted(request.Params?.Uri ?? string.Empty);
+                    return result;
+                }
+                catch (Exception e) when (e is not OperationCanceledException and not McpProtocolException)
+                {
+                    ReadResourceError(request.Params?.Uri ?? string.Empty, e);
+                    throw;
+                }
             });
         subscribeHandler = BuildFilterPipeline(subscribeHandler, options.Filters.SubscribeToResourcesFilters);
         unsubscribeHandler = BuildFilterPipeline(unsubscribeHandler, options.Filters.UnsubscribeFromResourcesFilters);
@@ -487,7 +497,7 @@ await originalListPromptsHandler(request, cancellationToken).ConfigureAwait(fals
 
         listPromptsHandler = BuildFilterPipeline(listPromptsHandler, options.Filters.ListPromptsFilters);
         getPromptHandler = BuildFilterPipeline(getPromptHandler, options.Filters.GetPromptFilters, handler =>
-            (request, cancellationToken) =>
+            async (request, cancellationToken) =>
             {
                 // Initial handler that sets MatchedPrimitive
                 if (request.Params?.Name is { } promptName && prompts is not null &&
@@ -496,7 +506,17 @@ await originalListPromptsHandler(request, cancellationToken).ConfigureAwait(fals
                     request.MatchedPrimitive = prompt;
                 }
 
-                return handler(request, cancellationToken);
+                try
+                {
+                    var result = await handler(request, cancellationToken).ConfigureAwait(false);
+                    GetPromptCompleted(request.Params?.Name ?? string.Empty);
+                    return result;
+                }
+                catch (Exception e) when (e is not OperationCanceledException and not McpProtocolException)
+                {
+                    GetPromptError(request.Params?.Name ?? string.Empty, e);
+                    throw;
+                }
             });
 
         ServerCapabilities.Prompts.ListChanged = listChanged;
@@ -610,7 +630,16 @@ await originalListToolsHandler(request, cancellationToken).ConfigureAwait(false)
 
                 try
                 {
-                    return await handler(request, cancellationToken).ConfigureAwait(false);
+                    var result = await handler(request, cancellationToken).ConfigureAwait(false);
+
+                    // Don't log here for task-augmented calls; logging happens asynchronously
+                    // in ExecuteToolAsTaskAsync when the tool actually completes.
+                    if (result.Task is null)
+                    {
+                        ToolCallCompleted(request.Params?.Name ?? string.Empty, result.IsError is true);
+                    }
+
+                    return result;
                 }
                 catch (Exception e) when (e is not OperationCanceledException and not McpProtocolException)
                 {
@@ -944,6 +973,21 @@ internal static LoggingLevel ToLoggingLevel(LogLevel level) =>
     [LoggerMessage(Level = LogLevel.Error, Message = "\"{ToolName}\" threw an unhandled exception.")]
     private partial void ToolCallError(string toolName, Exception exception);
 
+    [LoggerMessage(Level = LogLevel.Information, Message = "\"{ToolName}\" completed. IsError = {IsError}.")]
+    private partial void ToolCallCompleted(string toolName, bool isError);
+
+    [LoggerMessage(Level = LogLevel.Error, Message = "GetPrompt \"{PromptName}\" threw an unhandled exception.")]
+    private partial void GetPromptError(string promptName, Exception exception);
+
+    [LoggerMessage(Level = LogLevel.Information, Message = "GetPrompt \"{PromptName}\" completed.")]
+    private partial void GetPromptCompleted(string promptName);
+
+    [LoggerMessage(Level = LogLevel.Error, Message = "ReadResource \"{ResourceUri}\" threw an unhandled exception.")]
+    private partial void ReadResourceError(string resourceUri, Exception exception);
+
+    [LoggerMessage(Level = LogLevel.Information, Message = "ReadResource \"{ResourceUri}\" completed.")]
+    private partial void ReadResourceCompleted(string resourceUri);
+
     /// <summary>
     /// Executes a tool call as a task and returns a CallToolTaskResult immediately.
     /// </summary>
@@ -1004,6 +1048,7 @@ private async ValueTask<CallToolResult> ExecuteToolAsTaskAsync(
 
                 // Invoke the tool with task-specific cancellation token
                 var result = await tool.InvokeAsync(request, taskCancellationToken).ConfigureAwait(false);
+                ToolCallCompleted(request.Params?.Name ?? string.Empty, result.IsError is true);
 
                 // Determine final status based on whether there was an error
                 var finalStatus = result.IsError is true ? McpTaskStatus.Failed : McpTaskStatus.Completed;

tests/ModelContextProtocol.Tests/Configuration/McpServerBuilderExtensionsPromptsTests.cs

@@ -1,5 +1,6 @@
 using Microsoft.Extensions.AI;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using ModelContextProtocol.Client;
 using ModelContextProtocol.Protocol;
@@ -195,6 +196,37 @@ await Assert.ThrowsAsync<McpProtocolException>(async () => await client.GetPromp
             cancellationToken: TestContext.Current.CancellationToken));
     }
 
+    [Fact]
+    public async Task Logs_Prompt_Name_On_Successful_Call()
+    {
+        await using McpClient client = await CreateMcpClientForServer();
+
+        var result = await client.GetPromptAsync(
+            "returns_chat_messages",
+            new Dictionary<string, object?> { ["message"] = "hello" },
+            cancellationToken: TestContext.Current.CancellationToken);
+
+        Assert.NotNull(result);
+
+        var infoLog = Assert.Single(MockLoggerProvider.LogMessages, m => m.Message == "GetPrompt \"returns_chat_messages\" completed.");
+        Assert.Equal(LogLevel.Information, infoLog.LogLevel);
+    }
+
+    [Fact]
+    public async Task Logs_Prompt_Name_When_Prompt_Throws()
+    {
+        await using McpClient client = await CreateMcpClientForServer();
+
+        await Assert.ThrowsAsync<McpProtocolException>(async () => await client.GetPromptAsync(
+            "throws_exception",
+            new Dictionary<string, object?> { ["message"] = "test" },
+            cancellationToken: TestContext.Current.CancellationToken));
+
+        var errorLog = Assert.Single(MockLoggerProvider.LogMessages, m => m.LogLevel == LogLevel.Error);
+        Assert.Equal("GetPrompt \"throws_exception\" threw an unhandled exception.", errorLog.Message);
+        Assert.IsType<FormatException>(errorLog.Exception);
+    }
+
     [Fact]
     public async Task Throws_Exception_On_Unknown_Prompt()
     {

tests/ModelContextProtocol.Tests/Configuration/McpServerBuilderExtensionsResourcesTests.cs

@@ -1,5 +1,6 @@
 using Microsoft.Extensions.AI;
 using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using ModelContextProtocol.Client;
 using ModelContextProtocol.Protocol;
@@ -239,6 +240,35 @@ await Assert.ThrowsAsync<McpProtocolException>(async () => await client.ReadReso
             cancellationToken: TestContext.Current.CancellationToken));
     }
 
+    [Fact]
+    public async Task Logs_Resource_Uri_On_Successful_Read()
+    {
+        await using McpClient client = await CreateMcpClientForServer();
+
+        var result = await client.ReadResourceAsync(
+            "resource://mcp/some_neat_direct_resource",
+            cancellationToken: TestContext.Current.CancellationToken);
+
+        Assert.NotNull(result);
+
+        var infoLog = Assert.Single(MockLoggerProvider.LogMessages, m => m.Message == "ReadResource \"resource://mcp/some_neat_direct_resource\" completed.");
+        Assert.Equal(LogLevel.Information, infoLog.LogLevel);
+    }
+
+    [Fact]
+    public async Task Logs_Resource_Uri_When_Resource_Throws()
+    {
+        await using McpClient client = await CreateMcpClientForServer();
+
+        await Assert.ThrowsAsync<McpProtocolException>(async () => await client.ReadResourceAsync(
+            "resource://mcp/throws_exception",
+            cancellationToken: TestContext.Current.CancellationToken));
+
+        var errorLog = Assert.Single(MockLoggerProvider.LogMessages, m => m.LogLevel == LogLevel.Error);
+        Assert.Equal("ReadResource \"resource://mcp/throws_exception\" threw an unhandled exception.", errorLog.Message);
+        Assert.IsType<InvalidOperationException>(errorLog.Exception);
+    }
+
     [Fact]
     public async Task Throws_Exception_On_Unknown_Resource()
     {

tests/ModelContextProtocol.Tests/Configuration/McpServerBuilderExtensionsToolsTests.cs

@@ -127,7 +127,7 @@ public async Task Can_List_Registered_Tools()
         await using McpClient client = await CreateMcpClientForServer();
 
         var tools = await client.ListToolsAsync(cancellationToken: TestContext.Current.CancellationToken);
-        Assert.Equal(16, tools.Count);
+        Assert.Equal(17, tools.Count);
 
         McpClientTool echoTool = tools.First(t => t.Name == "echo");
         Assert.Equal("Echoes the input back to the client.", echoTool.Description);
@@ -165,7 +165,7 @@ public async Task Can_Create_Multiple_Servers_From_Options_And_List_Registered_T
                 cancellationToken: TestContext.Current.CancellationToken))
             {
                 var tools = await client.ListToolsAsync(cancellationToken: TestContext.Current.CancellationToken);
-                Assert.Equal(16, tools.Count);
+                Assert.Equal(17, tools.Count);
 
                 McpClientTool echoTool = tools.First(t => t.Name == "echo");
                 Assert.Equal("Echoes the input back to the client.", echoTool.Description);
@@ -191,7 +191,7 @@ public async Task Can_Be_Notified_Of_Tool_Changes()
         await using McpClient client = await CreateMcpClientForServer();
 
         var tools = await client.ListToolsAsync(cancellationToken: TestContext.Current.CancellationToken);
-        Assert.Equal(16, tools.Count);
+        Assert.Equal(17, tools.Count);
 
         Channel<JsonRpcNotification> listChanged = Channel.CreateUnbounded<JsonRpcNotification>();
         var notificationRead = listChanged.Reader.ReadAsync(TestContext.Current.CancellationToken);
@@ -212,7 +212,7 @@ public async Task Can_Be_Notified_Of_Tool_Changes()
             await notificationRead;
 
             tools = await client.ListToolsAsync(cancellationToken: TestContext.Current.CancellationToken);
-            Assert.Equal(17, tools.Count);
+            Assert.Equal(18, tools.Count);
             Assert.Contains(tools, t => t.Name == "NewTool");
 
             notificationRead = listChanged.Reader.ReadAsync(TestContext.Current.CancellationToken);
@@ -222,7 +222,7 @@ public async Task Can_Be_Notified_Of_Tool_Changes()
         }
 
         tools = await client.ListToolsAsync(cancellationToken: TestContext.Current.CancellationToken);
-        Assert.Equal(16, tools.Count);
+        Assert.Equal(17, tools.Count);
         Assert.DoesNotContain(tools, t => t.Name == "NewTool");
     }
 
@@ -380,6 +380,39 @@ public async Task Returns_IsError_Content_And_Logs_Error_When_Tool_Fails()
         Assert.Equal("Test error", errorLog.Exception.Message);
     }
 
+    [Fact]
+    public async Task Logs_Tool_Name_On_Successful_Call()
+    {
+        await using McpClient client = await CreateMcpClientForServer();
+
+        var result = await client.CallToolAsync(
+            "echo",
+            new Dictionary<string, object?> { ["message"] = "test" },
+            cancellationToken: TestContext.Current.CancellationToken);
+
+        Assert.True(result.IsError is not true);
+        Assert.Equal("hello test", (result.Content[0] as TextContentBlock)?.Text);
+
+        var infoLog = Assert.Single(MockLoggerProvider.LogMessages, m => m.Message == "\"echo\" completed. IsError = False.");
+        Assert.Equal(LogLevel.Information, infoLog.LogLevel);
+    }
+
+    [Fact]
+    public async Task Logs_Tool_Name_With_IsError_When_Tool_Returns_Error()
+    {
+        await using McpClient client = await CreateMcpClientForServer();
+
+        var result = await client.CallToolAsync(
+            "return_is_error",
+            cancellationToken: TestContext.Current.CancellationToken);
+
+        Assert.True(result.IsError);
+        Assert.Contains("Tool returned an error", (result.Content[0] as TextContentBlock)?.Text);
+
+        var infoLog = Assert.Single(MockLoggerProvider.LogMessages, m => m.Message == "\"return_is_error\" completed. IsError = True.");
+        Assert.Equal(LogLevel.Information, infoLog.LogLevel);
+    }
+
     [Fact]
     public async Task Throws_Exception_On_Unknown_Tool()
     {
@@ -786,6 +819,16 @@ public static string ThrowException()
             throw new InvalidOperationException("Test error");
         }
 
+        [McpServerTool]
+        public static CallToolResult ReturnIsError()
+        {
+            return new CallToolResult
+            {
+                IsError = true,
+                Content = [new TextContentBlock { Text = "Tool returned an error" }],
+            };
+        }
+
         [McpServerTool]
         public static int ReturnCancellationToken(CancellationToken cancellationToken)
         {
@@ -868,5 +911,6 @@ public class ComplexObject
     [JsonSerializable(typeof(ComplexObject))]
     [JsonSerializable(typeof(string[]))]
     [JsonSerializable(typeof(JsonElement))]
+    [JsonSerializable(typeof(CallToolResult))]
     partial class BuilderToolsJsonContext : JsonSerializerContext;
 }