feat: opt in to output schema validation

dap-was-lib/src/main/java/io/shinhanlife/dap/lib/annotation/McpOutputSchema.java

@@ -0,0 +1,14 @@
+package io.shinhanlife.dap.lib.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Marks a response DTO whose generated JSON Schema must be exposed and validated for a Tool response.
+ */
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface McpOutputSchema {
+}

dap-was-lib/src/main/java/io/shinhanlife/dap/lib/util/JsonSchemaGenerator.java

@@ -76,7 +76,8 @@ public class JsonSchemaGenerator {
                 if (!schemaAnnotation.description().isEmpty() && !fieldSchema.containsKey("description")) {
                     fieldSchema.put("description", schemaAnnotation.description());
                 }
-                if (schemaAnnotation.required() && !requiredList.contains(field.getName())) {
+                if ((schemaAnnotation.required() || schemaAnnotation.requiredMode() == Schema.RequiredMode.REQUIRED)
+                        && !requiredList.contains(field.getName())) {
                     requiredList.add(field.getName());
                 }
                 if (!schemaAnnotation.pattern().isEmpty()) {

dap-was-lib/src/main/java/io/shinhanlife/dap/lib/util/ToolSchemaResolver.java

@@ -2,14 +2,13 @@ package io.shinhanlife.dap.lib.util;
 
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
-// removed McpOutputSchema
+import io.shinhanlife.dap.lib.annotation.McpOutputSchema;
+import io.shinhanlife.dap.lib.annotation.ToolHint;
 import java.io.InputStream;
 import java.util.Map;
 import org.springframework.core.io.ClassPathResource;
 
-import io.shinhanlife.dap.lib.annotation.ToolHint;
-
-/** Resolves an MCP Tool input schema from resource, inline value, or DTO metadata. */
+/** Resolves MCP Tool schemas from resources or DTO metadata. */
 public class ToolSchemaResolver {
 
     private final ObjectMapper objectMapper;
@@ -18,7 +17,8 @@ public class ToolSchemaResolver {
         this.objectMapper = objectMapper;
     }
 
-    public Map<String, Object> resolve(org.springaicommunity.mcp.annotation.McpTool function, ToolHint hint, Class<?> requestType) {
+    public Map<String, Object> resolve(org.springaicommunity.mcp.annotation.McpTool function,
+                                       ToolHint hint, Class<?> requestType) {
         if (hint != null && !hint.inputSchemaResource().isBlank()) {
             return loadResource(hint.inputSchemaResource());
         }
@@ -26,12 +26,11 @@ public class ToolSchemaResolver {
     }
 
     /**
-     * Resolves an explicitly declared response schema.
-     * Response schemas are opt-in so existing tools keep their current response behavior.
-     * ToolHint.outputSchemaResource()가 있으면 classpath JSON 파일에서 로드하고,
-     * 없으면 responseType DTO를 분석하여 자동 생성합니다.
+     * Resolves a response schema only when it is explicitly declared.
+     * A JSON resource has precedence over a DTO marker annotation.
      */
-    public Map<String, Object> resolveOutput(org.springaicommunity.mcp.annotation.McpTool function, Class<?> responseType, ToolHint hint) {
+    public Map<String, Object> resolveOutput(org.springaicommunity.mcp.annotation.McpTool function,
+                                             Class<?> responseType, ToolHint hint) {
         if (hint != null && !hint.outputSchemaResource().isBlank()) {
             return loadResource(hint.outputSchemaResource());
         }
@@ -39,16 +38,16 @@ public class ToolSchemaResolver {
     }
 
     /**
-     * Resolves an explicitly declared response schema.
-     * Response schemas are opt-in so existing tools keep their current response behavior.
+     * Generates a response schema only for DTOs marked with {@link McpOutputSchema}.
      */
-    public Map<String, Object> resolveOutput(org.springaicommunity.mcp.annotation.McpTool function, Class<?> responseType) {
-        // Object, Map 등 구체적인 DTO가 아닌 경우 검증 스킵
+    public Map<String, Object> resolveOutput(org.springaicommunity.mcp.annotation.McpTool function,
+                                             Class<?> responseType) {
         if (responseType == null
                 || responseType == Object.class
                 || Map.class.isAssignableFrom(responseType)
                 || responseType == Void.class
-                || responseType == void.class) {
+                || responseType == void.class
+                || !responseType.isAnnotationPresent(McpOutputSchema.class)) {
             return Map.of();
         }
         return JsonSchemaGenerator.generateSchema(responseType);
@@ -58,7 +57,7 @@ public class ToolSchemaResolver {
      * Retained for callers that use only explicit output schemas.
      */
     public Map<String, Object> resolveOutput(org.springaicommunity.mcp.annotation.McpTool function) {
-        return resolveOutput(function, null);
+        return Map.of();
     }
 
     private Map<String, Object> loadResource(String location) {
@@ -76,12 +75,4 @@ public class ToolSchemaResolver {
             throw new IllegalStateException("Failed to load MCP schema resource: " + location, e);
         }
     }
-
-    private Map<String, Object> parse(String schema, String source) {
-        try {
-            return objectMapper.readValue(schema, new TypeReference<>() { });
-        } catch (Exception e) {
-            throw new IllegalStateException("Failed to parse MCP input schema from " + source, e);
-        }
-    }
-}
+}