fix: Add missing logging for Async MCP Servers

Author: vorburger

core/src/main/java/com/google/adk/tools/mcp/McpServerLogConsumer.java

@@ -24,10 +24,11 @@
 
 class McpServerLogConsumer implements Consumer<LoggingMessageNotification> {
 
+  private static final Logger LOG = LoggerFactory.getLogger(McpServerLogConsumer.class);
+
   @Override
   public void accept(LoggingMessageNotification notif) {
-    Logger log = LoggerFactory.getLogger(notif.logger());
-    log.atLevel(convert(notif.level())).log("{}", notif.data());
+    LOG.atLevel(convert(notif.level())).log("{}", notif.data());
   }
 
   private Level convert(McpSchema.LoggingLevel level) {

core/src/main/java/com/google/adk/tools/mcp/McpSessionManager.java

@@ -16,16 +16,21 @@
 
 package com.google.adk.tools.mcp;
 
+import java.time.Duration;
+import java.util.Optional;
+import java.util.function.Function;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import io.modelcontextprotocol.client.McpAsyncClient;
 import io.modelcontextprotocol.client.McpClient;
 import io.modelcontextprotocol.client.McpSyncClient;
 import io.modelcontextprotocol.spec.McpClientTransport;
+import io.modelcontextprotocol.spec.McpSchema;
 import io.modelcontextprotocol.spec.McpSchema.ClientCapabilities;
 import io.modelcontextprotocol.spec.McpSchema.InitializeResult;
-import java.time.Duration;
-import java.util.Optional;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import reactor.core.publisher.Mono;
 
 /**
  * Manages MCP client sessions.
@@ -113,6 +118,16 @@ public static McpAsyncClient initializeAsyncSession(
             initializationTimeout == null ? Duration.ofMinutes(5) : initializationTimeout)
         .requestTimeout(requestTimeout == null ? Duration.ofMinutes(5) : requestTimeout)
         .capabilities(ClientCapabilities.builder().build())
+        .loggingConsumer(asyncMcpServerLogConsumer())
         .build();
   }
+
+  private static Function<McpSchema.LoggingMessageNotification, Mono<Void>>
+      asyncMcpServerLogConsumer() {
+    var syncConsumer = new McpServerLogConsumer();
+    return message -> {
+      syncConsumer.accept(message);
+      return Mono.empty();
+    };
+  }
 }