Log tool call name on success, not just failure

src/ModelContextProtocol.Core/Server/McpServerImpl.cs

@@ -610,7 +610,9 @@ await originalListToolsHandler(request, cancellationToken).ConfigureAwait(false)
 
                 try
                 {
-                    return await handler(request, cancellationToken).ConfigureAwait(false);
+                    var result = await handler(request, cancellationToken).ConfigureAwait(false);
+                    ToolCallCompleted(request.Params?.Name ?? string.Empty);
+                    return result;
                 }
                 catch (Exception e) when (e is not OperationCanceledException and not McpProtocolException)
                 {
@@ -944,6 +946,9 @@ 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 successfully.")]
+    private partial void ToolCallCompleted(string toolName);
+
     /// <summary>
     /// Executes a tool call as a task and returns a CallToolTaskResult immediately.
     /// </summary>
@@ -1008,6 +1013,11 @@ private async ValueTask<CallToolResult> ExecuteToolAsTaskAsync(
                 // Determine final status based on whether there was an error
                 var finalStatus = result.IsError is true ? McpTaskStatus.Failed : McpTaskStatus.Completed;
 
+                if (finalStatus == McpTaskStatus.Completed)
+                {
+                    ToolCallCompleted(request.Params?.Name ?? string.Empty);
+                }
+
                 // Store the result (serialize to JsonElement)
                 var resultElement = JsonSerializer.SerializeToElement(result, McpJsonUtilities.JsonContext.Default.CallToolResult);
                 var finalTask = await taskStore.StoreTaskResultAsync(

tests/ModelContextProtocol.Tests/Configuration/McpServerBuilderExtensionsToolsTests.cs

@@ -380,6 +380,23 @@ 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 successfully.");
+        Assert.Equal(LogLevel.Information, infoLog.LogLevel);
+    }
+
     [Fact]
     public async Task Throws_Exception_On_Unknown_Tool()
     {