diff --git a/examples/fel-example/04-output-parser/src/main/java/modelengine/example/ai/chat/parser/OutputParserExampleController.java b/examples/fel-example/04-output-parser/src/main/java/modelengine/example/ai/chat/parser/OutputParserExampleController.java
index 888784756..21d50ea59 100644
--- a/examples/fel-example/04-output-parser/src/main/java/modelengine/example/ai/chat/parser/OutputParserExampleController.java
+++ b/examples/fel-example/04-output-parser/src/main/java/modelengine/example/ai/chat/parser/OutputParserExampleController.java
@@ -20,6 +20,7 @@
 import modelengine.fit.http.annotation.RequestMapping;
 import modelengine.fit.http.annotation.RequestParam;
 import modelengine.fitframework.annotation.Component;
+import modelengine.fitframework.annotation.Fit;
 import modelengine.fitframework.annotation.Property;
 import modelengine.fitframework.annotation.Value;
 import modelengine.fitframework.flowable.Choir;
@@ -42,7 +43,7 @@ public class OutputParserExampleController {
     @Value("${example.model}")
     private String modelName;
 
-    public OutputParserExampleController(ChatModel chatModel, ObjectSerializer serializer) {
+    public OutputParserExampleController(ChatModel chatModel, @Fit(alias = "json") ObjectSerializer serializer) {
         this.chatModel = chatModel;
         this.outputParser = JsonOutputParser.createPartial(serializer, Demo.class);
         this.template = new HumanMessageTemplate(new DefaultStringTemplate(
diff --git a/examples/fel-example/05-retrieval/src/main/java/modelengine/example/ai/chat/retrieval/RetrievalExampleController.java b/examples/fel-example/05-retrieval/src/main/java/modelengine/example/ai/chat/retrieval/RetrievalExampleController.java
index c1b3a4102..2444ddfd7 100644
--- a/examples/fel-example/05-retrieval/src/main/java/modelengine/example/ai/chat/retrieval/RetrievalExampleController.java
+++ b/examples/fel-example/05-retrieval/src/main/java/modelengine/example/ai/chat/retrieval/RetrievalExampleController.java
@@ -39,6 +39,7 @@
 import modelengine.fit.http.annotation.RequestMapping;
 import modelengine.fit.http.annotation.RequestParam;
 import modelengine.fitframework.annotation.Component;
+import modelengine.fitframework.annotation.Fit;
 import modelengine.fitframework.annotation.Value;
 import modelengine.fitframework.serialization.ObjectSerializer;
 import modelengine.fitframework.util.FileUtils;
@@ -65,8 +66,8 @@ public class RetrievalExampleController {
     private final AiProcessFlow<String, ChatMessage> ragFlow;
     private final Memory memory = new CacheMemory();
 
-    public RetrievalExampleController(ChatModel chatModel, EmbedModel embedModel, ObjectSerializer serializer,
-            @Value("${example.model.chat}") String chatModelName,
+    public RetrievalExampleController(ChatModel chatModel, EmbedModel embedModel,
+            @Fit(alias = "json") ObjectSerializer serializer, @Value("${example.model.chat}") String chatModelName,
             @Value("${example.model.embed}") String embedModelName) {
         DocumentEmbedModel documentEmbedModel =
                 new DefaultDocumentEmbedModel(embedModel, EmbedOption.custom().model(embedModelName).build());
diff --git a/framework/fel/java/plugins/tool-discoverer/src/main/java/modelengine/fel/tool/support/DefaultToolDiscoverer.java b/framework/fel/java/plugins/tool-discoverer/src/main/java/modelengine/fel/tool/support/DefaultToolDiscoverer.java
index 74d586ab8..65a5843e4 100644
--- a/framework/fel/java/plugins/tool-discoverer/src/main/java/modelengine/fel/tool/support/DefaultToolDiscoverer.java
+++ b/framework/fel/java/plugins/tool-discoverer/src/main/java/modelengine/fel/tool/support/DefaultToolDiscoverer.java
@@ -10,12 +10,13 @@
 import static modelengine.fitframework.inspection.Validation.notNull;
 
 import modelengine.fel.tool.ToolInfoEntity;
-import modelengine.fel.tool.info.entity.ToolEntity;
 import modelengine.fel.tool.ToolSchema;
+import modelengine.fel.tool.info.entity.ToolEntity;
 import modelengine.fel.tool.info.entity.ToolGroupEntity;
 import modelengine.fel.tool.info.entity.ToolJsonEntity;
 import modelengine.fel.tool.service.ToolRepository;
 import modelengine.fitframework.annotation.Component;
+import modelengine.fitframework.annotation.Fit;
 import modelengine.fitframework.annotation.Value;
 import modelengine.fitframework.plugin.Plugin;
 import modelengine.fitframework.plugin.PluginStartedObserver;
@@ -42,7 +43,6 @@
  */
 @Component
 public class DefaultToolDiscoverer implements PluginStartedObserver, PluginStoppingObserver {
-    private static final String TOOLS = "tools";
     private final ToolRepository toolRepository;
     private final ObjectSerializer serializer;
     private final int maxToolNum;
@@ -55,7 +55,7 @@ public class DefaultToolDiscoverer implements PluginStartedObserver, PluginStopp
      * @param maxNum 表示插件最大工具数量的 {@code int}。
      * @throws IllegalArgumentException 当 {@code toolRepository}、{@code objectSerializer} 为 {@code null} 时。
      */
-    public DefaultToolDiscoverer(ToolRepository toolRepository, ObjectSerializer serializer,
+    public DefaultToolDiscoverer(ToolRepository toolRepository, @Fit(alias = "json") ObjectSerializer serializer,
             @Value("${tool.max-num}") int maxNum) {
         this.toolRepository = notNull(toolRepository, "The tool repository cannot be null.");
         this.serializer = notNull(serializer, "The serializer cannot be null.");
@@ -94,7 +94,8 @@ private List<ToolEntity> parseTools(Resource resource) {
             if (toolJsonEntity == null) {
                 return Collections.emptyList();
             }
-            return toolJsonEntity.getToolGroups().stream()
+            return toolJsonEntity.getToolGroups()
+                    .stream()
                     .filter(Objects::nonNull)
                     .map(ToolGroupEntity::getTools)
                     .filter(Objects::nonNull)