Meh. Giving the routing a de facto "preview" mode for the describe co…

src/Wolverine/Runtime/Routing/MessageRoute.cs

@@ -27,14 +27,25 @@ public MessageRoute(Type messageType, Endpoint endpoint, IReplyTracker replies)
         IsLocal = endpoint is LocalQueue;
         _replyTracker = replies;
 
-        Sender = endpoint.Agent ?? throw new ArgumentOutOfRangeException(nameof(endpoint), $"Endpoint {endpoint.Uri} does not have an active sending agent. Message type: {messageType.FullNameInCode()}");
+        if (WolverineSystemPart.WithinDescription)
+        {
+            Sender = endpoint.Agent;
+        }
+        else
+        {
+            Sender = endpoint.Agent ?? throw new ArgumentOutOfRangeException(nameof(endpoint), $"Endpoint {endpoint.Uri} does not have an active sending agent. Message type: {messageType.FullNameInCode()}");
+        }
 
         IsLocal = endpoint is LocalQueue;
 
         if (messageType.CanBeCastTo(typeof(ISerializable)))
         {
             Serializer = typeof(IntrinsicSerializer<>).CloseAndBuildAs<IMessageSerializer>(messageType);
         }
+        else if (WolverineSystemPart.WithinDescription)
+        {
+            Serializer = endpoint.DefaultSerializer;
+        }
         else
         {
             Serializer = endpoint.DefaultSerializer ?? throw new ArgumentOutOfRangeException(nameof(endpoint), "No DefaultSerializer on endpoint " + endpoint.Uri + ", Message type: " + messageType.FullNameInCode());
@@ -48,6 +59,8 @@ public MessageRoute(Type messageType, Endpoint endpoint, IReplyTracker replies)
         _endpoint = endpoint;
     }
 
+    public Uri Uri => _endpoint.Uri;
+
     public Type MessageType { get; }
 
     public bool IsLocal { get; }

src/Wolverine/Runtime/Routing/MessageRouter.cs

@@ -11,8 +11,10 @@ public MessageRouter(WolverineRuntime runtime, IEnumerable<IMessageRoute> routes
         Routes = routes.ToArray();
 
         // ReSharper disable once VirtualMemberCallInConstructor
-        foreach (var route in Routes.OfType<MessageRoute>().Where(x => x.Sender.Endpoint is LocalQueue))
+        foreach (var route in Routes.OfType<MessageRoute>().Where(x => x.Sender?.Endpoint is LocalQueue))
+        {
             route.Rules.Fill(HandlerRules);
+        }
     }
 
     public override IMessageRoute[] Routes { get; }

src/Wolverine/WolverineSystemPart.cs

@@ -14,6 +14,8 @@ namespace Wolverine;
 
 internal class WolverineSystemPart : SystemPartBase
 {
+    public static bool WithinDescription = false;
+
     private readonly WolverineRuntime _runtime;
 
     public WolverineSystemPart(IWolverineRuntime runtime) : base("Wolverine", new Uri("wolverine://" + runtime.Options.ServiceName))
@@ -23,6 +25,7 @@ internal class WolverineSystemPart : SystemPartBase
 
     public override async Task WriteToConsole()
     {
+        WithinDescription = true;
         await _runtime.StartLightweightAsync();
 
         _runtime.Options.WriteToConsole();
@@ -56,8 +59,8 @@ public void WriteMessageSubscriptions()
             var routes = _runtime.RoutingFor(messageType).Routes;
             foreach (var route in routes.OfType<MessageRoute>())
             {
-                table.AddRow(messageType.FullNameInCode(), route.Sender.Destination.ToString(),
-                    route.Serializer.ContentType);
+                table.AddRow(messageType.FullNameInCode(), route.Uri.ToString(),
+                    route.Serializer?.ContentType ?? "application/json");
             }
         }