diff --git a/installer/webhook-server.iss b/installer/webhook-server.iss
index 8f14e2b..562546b 100644
--- a/installer/webhook-server.iss
+++ b/installer/webhook-server.iss
@@ -70,10 +70,14 @@ Filename: "powershell.exe"; \
     Parameters: "-NoProfile -ExecutionPolicy Bypass -File ""{app}\scripts\install-service.ps1"" -BinaryPath ""{app}\{#ServiceExeName}"""; \
     StatusMsg: "Installing Windows Service..."; \
     Flags: runhidden
-; No post-install GUI launch: the GUI is requireAdministrator and the launch
-; from the installer wizard ends up un-elevated for the post-install user, so
-; it would just fail to connect to the admin pipe. The Start Menu shortcut
-; handles the elevation correctly via the embedded manifest.
+; Post-install GUI launch. The GUI's app.manifest is requireAdministrator,
+; so launching with shellexec (ShellExecute) honors the manifest and triggers
+; a clean UAC prompt. Using plain CreateProcess via the default Run path
+; would skip the manifest and result in an un-elevated GUI that cannot connect
+; to the admin pipe.
+Filename: "{app}\{#AppExeName}"; \
+    Description: "Launch {#AppName}"; \
+    Flags: postinstall nowait shellexec skipifsilent
 
 [UninstallRun]
 Filename: "powershell.exe"; \
diff --git a/src/WebhookServer.Core/Ipc/AdminProtocol.cs b/src/WebhookServer.Core/Ipc/AdminProtocol.cs
index 6977ccb..449eb58 100644
--- a/src/WebhookServer.Core/Ipc/AdminProtocol.cs
+++ b/src/WebhookServer.Core/Ipc/AdminProtocol.cs
@@ -34,6 +34,7 @@ public sealed class BackupEntry
     public string FileName { get; set; } = "";
     public DateTimeOffset SavedAt { get; set; }
     public long SizeBytes { get; set; }
+    public string? Description { get; set; }
 }
 
 public sealed class RestoreBackupArgs
@@ -41,6 +42,11 @@ public sealed class RestoreBackupArgs
     public string FileName { get; set; } = "";
 }
 
+public sealed class CreateCheckpointArgs
+{
+    public string? Description { get; set; }
+}
+
 public sealed class AdminRequest
 {
     [JsonPropertyName("op")] public string Op { get; set; } = "";
diff --git a/src/WebhookServer.Core/Storage/ConfigStore.cs b/src/WebhookServer.Core/Storage/ConfigStore.cs
index 2f6daa3..e8d5417 100644
--- a/src/WebhookServer.Core/Storage/ConfigStore.cs
+++ b/src/WebhookServer.Core/Storage/ConfigStore.cs
@@ -48,7 +48,14 @@ public sealed class ConfigStore
                 Directory.CreateDirectory(backupsDir);
                 var stamp = DateTime.UtcNow.ToString("yyyyMMdd-HHmmss");
                 var backupPath = System.IO.Path.Combine(backupsDir, $"config-{stamp}.json");
-                File.Copy(Path, backupPath, overwrite: false);
+                if (!File.Exists(backupPath))
+                {
+                    File.Copy(Path, backupPath, overwrite: false);
+                    var sidecar = new { description = "Before save", reason = "before-save" };
+                    File.WriteAllText(
+                        System.IO.Path.ChangeExtension(backupPath, ".meta.json"),
+                        JsonSerializer.Serialize(sidecar, ConfigJson.Compact));
+                }
                 PruneBackups(backupsDir, retain: 30);
             }
             catch
@@ -71,11 +78,18 @@ public sealed class ConfigStore
     private static void PruneBackups(string backupsDir, int retain)
     {
         var stale = new DirectoryInfo(backupsDir).GetFiles("config-*.json")
+            .Where(f => !f.Name.EndsWith(".meta.json", StringComparison.OrdinalIgnoreCase))
             .OrderByDescending(f => f.Name)
             .Skip(retain);
         foreach (var f in stale)
         {
-            try { f.Delete(); } catch { }
+            try
+            {
+                f.Delete();
+                var sidecar = System.IO.Path.ChangeExtension(f.FullName, ".meta.json");
+                if (File.Exists(sidecar)) File.Delete(sidecar);
+            }
+            catch { }
         }
     }
 
diff --git a/src/WebhookServer.Gui/Services/AdminPipeClient.cs b/src/WebhookServer.Gui/Services/AdminPipeClient.cs
index 300d3f0..3611aaa 100644
--- a/src/WebhookServer.Gui/Services/AdminPipeClient.cs
+++ b/src/WebhookServer.Gui/Services/AdminPipeClient.cs
@@ -101,6 +101,6 @@ public sealed class AdminPipeClient
     public Task<AdminResponse> ImportConfigAsync(ServerConfig config, CancellationToken ct = default) =>
         InvokeAsync(AdminOps.ImportConfig, config, ct);
 
-    public Task<BackupEntry?> CreateCheckpointAsync(CancellationToken ct = default) =>
-        InvokeAsync<BackupEntry>(AdminOps.CreateCheckpoint, null, ct);
+    public Task<BackupEntry?> CreateCheckpointAsync(string? description, CancellationToken ct = default) =>
+        InvokeAsync<BackupEntry>(AdminOps.CreateCheckpoint, new CreateCheckpointArgs { Description = description }, ct);
 }
diff --git a/src/WebhookServer.Gui/ViewModels/ConfigCheckpointsViewModel.cs b/src/WebhookServer.Gui/ViewModels/ConfigCheckpointsViewModel.cs
index 72e6797..d0fa3fc 100644
--- a/src/WebhookServer.Gui/ViewModels/ConfigCheckpointsViewModel.cs
+++ b/src/WebhookServer.Gui/ViewModels/ConfigCheckpointsViewModel.cs
@@ -46,9 +46,20 @@ public sealed partial class ConfigCheckpointsViewModel : ObservableObject
     [RelayCommand]
     private async Task TakeCheckpointAsync()
     {
+        // Prompt for an optional description on the UI thread.
+        string? description = null;
+        var prompted = Application.Current.Dispatcher.Invoke(() =>
+        {
+            var dlg = new Views.TakeCheckpointDialog { Owner = Application.Current.MainWindow };
+            if (dlg.ShowDialog() != true) return false;
+            description = string.IsNullOrWhiteSpace(dlg.Description) ? null : dlg.Description;
+            return true;
+        });
+        if (!prompted) return;
+
         try
         {
-            var entry = await _client.CreateCheckpointAsync().ConfigureAwait(false);
+            var entry = await _client.CreateCheckpointAsync(description).ConfigureAwait(false);
             await RefreshAsync().ConfigureAwait(false);
             if (entry is not null)
             {
diff --git a/src/WebhookServer.Gui/Views/ConfigCheckpointsDialog.xaml b/src/WebhookServer.Gui/Views/ConfigCheckpointsDialog.xaml
index a4f70c8..45ce611 100644
--- a/src/WebhookServer.Gui/Views/ConfigCheckpointsDialog.xaml
+++ b/src/WebhookServer.Gui/Views/ConfigCheckpointsDialog.xaml
@@ -39,11 +39,13 @@
                   HeadersVisibility="Column"
                   GridLinesVisibility="Horizontal">
             <DataGrid.Columns>
-                <DataGridTextColumn Header="When (local)" Width="200"
+                <DataGridTextColumn Header="When (local)" Width="170"
                                     Binding="{Binding SavedAt, StringFormat='{}{0:yyyy-MM-dd HH:mm:ss}', ConverterCulture=en-US}"/>
+                <DataGridTextColumn Header="Description" Width="*"
+                                    Binding="{Binding Description}"/>
                 <DataGridTextColumn Header="Size" Width="100"
                                     Binding="{Binding SizeBytes, StringFormat='{}{0:n0} bytes'}"/>
-                <DataGridTextColumn Header="File name" Width="*"
+                <DataGridTextColumn Header="File name" Width="200"
                                     Binding="{Binding FileName}" FontFamily="Consolas"/>
             </DataGrid.Columns>
         </DataGrid>
diff --git a/src/WebhookServer.Gui/Views/TakeCheckpointDialog.xaml b/src/WebhookServer.Gui/Views/TakeCheckpointDialog.xaml
new file mode 100644
index 0000000..0591b88
--- /dev/null
+++ b/src/WebhookServer.Gui/Views/TakeCheckpointDialog.xaml
@@ -0,0 +1,34 @@
+<Window x:Class="WebhookServer.Gui.Views.TakeCheckpointDialog"
+        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        Title="Take checkpoint"
+        Height="180" Width="440"
+        ResizeMode="NoResize"
+        WindowStartupLocation="CenterOwner"
+        Icon="/webhook-server.ico"
+        ShowInTaskbar="False">
+    <Grid Margin="16">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="Auto"/>
+            <RowDefinition Height="*"/>
+            <RowDefinition Height="Auto"/>
+        </Grid.RowDefinitions>
+
+        <TextBlock Grid.Row="0" TextWrapping="Wrap"
+                   Text="Description for this checkpoint (optional):"/>
+        <TextBox x:Name="DescriptionBox" Grid.Row="1" Margin="0,8,0,0" MaxLength="120">
+            <TextBox.InputBindings>
+                <KeyBinding Key="Enter" Command="{Binding OkCommand, ElementName=Self, FallbackValue={x:Null}}"/>
+            </TextBox.InputBindings>
+        </TextBox>
+        <TextBlock Grid.Row="2" Foreground="Gray" FontStyle="Italic" FontSize="11" Margin="0,4,0,0"
+                   Text="Examples: 'Before adding new endpoint', 'Pre-AD-policy-change'. Leave blank to use 'Manual checkpoint'."/>
+
+        <StackPanel Grid.Row="4" Orientation="Horizontal" HorizontalAlignment="Right" Margin="0,12,0,0">
+            <Button Content="OK" Width="80" IsDefault="True" Click="OnOk" Margin="0,0,8,0"/>
+            <Button Content="Cancel" Width="80" IsCancel="True" Click="OnCancel"/>
+        </StackPanel>
+    </Grid>
+</Window>
diff --git a/src/WebhookServer.Gui/Views/TakeCheckpointDialog.xaml.cs b/src/WebhookServer.Gui/Views/TakeCheckpointDialog.xaml.cs
new file mode 100644
index 0000000..aa43fd7
--- /dev/null
+++ b/src/WebhookServer.Gui/Views/TakeCheckpointDialog.xaml.cs
@@ -0,0 +1,27 @@
+using System.Windows;
+
+namespace WebhookServer.Gui.Views;
+
+public partial class TakeCheckpointDialog : Window
+{
+    public string Description { get; private set; } = "";
+
+    public TakeCheckpointDialog()
+    {
+        InitializeComponent();
+        Loaded += (_, _) => DescriptionBox.Focus();
+    }
+
+    private void OnOk(object sender, RoutedEventArgs e)
+    {
+        Description = DescriptionBox.Text?.Trim() ?? "";
+        DialogResult = true;
+        Close();
+    }
+
+    private void OnCancel(object sender, RoutedEventArgs e)
+    {
+        DialogResult = false;
+        Close();
+    }
+}
diff --git a/src/WebhookServer.Service/AdminPipeServer.cs b/src/WebhookServer.Service/AdminPipeServer.cs
index 053ed8f..37f27b8 100644
--- a/src/WebhookServer.Service/AdminPipeServer.cs
+++ b/src/WebhookServer.Service/AdminPipeServer.cs
@@ -227,8 +227,11 @@ internal sealed class AdminPipeServer : BackgroundService
 
             case AdminOps.CreateCheckpoint:
             {
-                var entry = CreateCheckpoint("manual");
-                _logger.LogInformation("Manual checkpoint created: {File}", entry.FileName);
+                var args = DeserializeData<CreateCheckpointArgs>(request);
+                var description = args?.Description;
+                if (string.IsNullOrWhiteSpace(description)) description = "Manual checkpoint";
+                var entry = CreateCheckpoint("manual", description);
+                _logger.LogInformation("Manual checkpoint created: {File} ({Desc})", entry.FileName, description);
                 return AdminResponse.Success(entry);
             }
 
@@ -238,10 +241,13 @@ internal sealed class AdminPipeServer : BackgroundService
     }
 
     /// <summary>
-    /// Snapshot the current config.json into the backups folder. Used both by the
-    /// "Take checkpoint now" GUI action and by the midnight scheduler.
+    /// Snapshot the current config.json into the backups folder. Used by the
+    /// "Take checkpoint now" GUI action, the midnight scheduler, and the
+    /// auto-on-save hook in ConfigStore. Description is stored in a sidecar
+    /// .meta.json file next to the snapshot so it survives restarts and can
+    /// be rendered in the GUI.
     /// </summary>
-    public static BackupEntry CreateCheckpoint(string reason)
+    public static BackupEntry CreateCheckpoint(string reason, string description)
     {
         var configPath = ServicePaths.ConfigPath;
         if (!File.Exists(configPath))
@@ -252,17 +258,23 @@ internal sealed class AdminPipeServer : BackgroundService
 
         var stamp = DateTime.UtcNow.ToString("yyyyMMdd-HHmmss");
         var dest = Path.Combine(dir, $"config-{stamp}.json");
-        // If we somehow snapshot twice in the same second, append a suffix.
         if (File.Exists(dest))
             dest = Path.Combine(dir, $"config-{stamp}-{reason}.json");
 
         File.Copy(configPath, dest);
+
+        // Write the sidecar metadata.
+        var sidecarPath = Path.ChangeExtension(dest, ".meta.json");
+        var sidecar = new { description, reason };
+        File.WriteAllText(sidecarPath, JsonSerializer.Serialize(sidecar, ConfigJson.Compact));
+
         var info = new FileInfo(dest);
         return new BackupEntry
         {
             FileName = info.Name,
             SavedAt = info.LastWriteTimeUtc,
             SizeBytes = info.Length,
+            Description = description,
         };
     }
 
@@ -271,6 +283,7 @@ internal sealed class AdminPipeServer : BackgroundService
         var dir = Path.Combine(ServicePaths.DataRoot, "backups");
         if (!Directory.Exists(dir)) return new List<BackupEntry>();
         return new DirectoryInfo(dir).GetFiles("config-*.json")
+            .Where(f => !f.Name.EndsWith(".meta.json", StringComparison.OrdinalIgnoreCase))
             .OrderByDescending(f => f.Name)
             .Take(50)
             .Select(f => new BackupEntry
@@ -278,10 +291,23 @@ internal sealed class AdminPipeServer : BackgroundService
                 FileName = f.Name,
                 SavedAt = f.LastWriteTimeUtc,
                 SizeBytes = f.Length,
+                Description = ReadSidecarDescription(f.FullName),
             })
             .ToList();
     }
 
+    private static string? ReadSidecarDescription(string snapshotPath)
+    {
+        try
+        {
+            var sidecarPath = Path.ChangeExtension(snapshotPath, ".meta.json");
+            if (!File.Exists(sidecarPath)) return null;
+            using var doc = JsonDocument.Parse(File.ReadAllText(sidecarPath));
+            return doc.RootElement.TryGetProperty("description", out var d) ? d.GetString() : null;
+        }
+        catch { return null; }
+    }
+
     private async Task<ServerConfig> RestoreBackupAsync(string fileName, CancellationToken ct)
     {
         // Refuse anything that tries to escape the backups directory.
diff --git a/src/WebhookServer.Service/CheckpointScheduler.cs b/src/WebhookServer.Service/CheckpointScheduler.cs
index 983f65e..cf9faa9 100644
--- a/src/WebhookServer.Service/CheckpointScheduler.cs
+++ b/src/WebhookServer.Service/CheckpointScheduler.cs
@@ -34,7 +34,7 @@ internal sealed class CheckpointScheduler : BackgroundService
 
             try
             {
-                var entry = AdminPipeServer.CreateCheckpoint("daily");
+                var entry = AdminPipeServer.CreateCheckpoint("daily", "Nightly auto-checkpoint");
                 _logger.LogInformation("Daily checkpoint created: {File}", entry.FileName);
             }
             catch (FileNotFoundException)