Address PR feedback.

Author: halter73

src/ModelContextProtocol/Client/AutoDetectingClientSessionTransport.cs

@@ -79,12 +79,12 @@ private async Task InitializeAsync(JsonRpcMessage message, CancellationToken can
             LogUsingStreamableHttp(_name);
             ActiveTransport = streamableHttpTransport;
         }
-        finally
+        catch
         {
-            if (ActiveTransport is null)
-            {
-                await streamableHttpTransport.DisposeAsync().ConfigureAwait(false);
-            }
+            // If nothing threw inside the try block, we've either set streamableHttpTransport as the
+            // ActiveTransport, or else we will have disposed it in the !IsSuccessStatusCode if statement.
+            await streamableHttpTransport.DisposeAsync().ConfigureAwait(false);
+            throw;
         }
     }
 

src/ModelContextProtocol/Client/SseClientTransport.cs

@@ -66,7 +66,7 @@ public async Task<ITransport> ConnectAsync(CancellationToken cancellationToken =
             case HttpTransportMode.Sse:
                 return await ConnectSseTransportAsync(cancellationToken).ConfigureAwait(false);
             default:
-                throw new ArgumentException($"Unsupported transport mode: {_options.TransportMode}", nameof(_options.TransportMode));
+                throw new InvalidOperationException($"Unsupported transport mode: {_options.TransportMode}");
         }
     }