feat(server): add utility functions for CallToolResult

api/kotlin-sdk.api

@@ -2492,6 +2492,13 @@ public final class io/modelcontextprotocol/kotlin/sdk/TypesKt {
 	public static final fun getSUPPORTED_PROTOCOL_VERSIONS ()[Ljava/lang/String;
 }
 
+public final class io/modelcontextprotocol/kotlin/sdk/Types_utilKt {
+	public static final fun error (Lio/modelcontextprotocol/kotlin/sdk/CallToolResult$Companion;Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;)Lio/modelcontextprotocol/kotlin/sdk/CallToolResult;
+	public static synthetic fun error$default (Lio/modelcontextprotocol/kotlin/sdk/CallToolResult$Companion;Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;ILjava/lang/Object;)Lio/modelcontextprotocol/kotlin/sdk/CallToolResult;
+	public static final fun ok (Lio/modelcontextprotocol/kotlin/sdk/CallToolResult$Companion;Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;)Lio/modelcontextprotocol/kotlin/sdk/CallToolResult;
+	public static synthetic fun ok$default (Lio/modelcontextprotocol/kotlin/sdk/CallToolResult$Companion;Ljava/lang/String;Lkotlinx/serialization/json/JsonObject;ILjava/lang/Object;)Lio/modelcontextprotocol/kotlin/sdk/CallToolResult;
+}
+
 public final class io/modelcontextprotocol/kotlin/sdk/UnknownContent : io/modelcontextprotocol/kotlin/sdk/PromptMessageContentTextOrImage {
 	public static final field Companion Lio/modelcontextprotocol/kotlin/sdk/UnknownContent$Companion;
 	public fun <init> (Ljava/lang/String;)V

src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/types.util.kt

@@ -294,4 +294,24 @@ public class RequestIdSerializer : KSerializer<RequestId> {
             is RequestId.NumberId -> jsonEncoder.encodeLong(value.value)
         }
     }
-}
+}
+
+/**
+ * Creates a [CallToolResult] with single [TextContent] and [meta].
+ */
+public fun CallToolResult.Companion.ok(content: String, meta: JsonObject = EmptyJsonObject): CallToolResult =
+    CallToolResult(
+        content = listOf(TextContent(content)),
+        isError = false,
+        _meta = meta
+    )
+
+/**
+ * Creates a [CallToolResult] with single [TextContent] and [meta], with `isError` being true.
+ */
+public fun CallToolResult.Companion.error(content: String, meta: JsonObject = EmptyJsonObject): CallToolResult =
+    CallToolResult(
+        content = listOf(TextContent(content)),
+        isError = true,
+        _meta = meta
+    )

src/commonTest/kotlin/CallToolResultUtilsTest.kt

@@ -0,0 +1,64 @@
+package io.modelcontextprotocol.kotlin.sdk
+
+import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.buildJsonObject
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertTrue
+
+class CallToolResultUtilsTest {
+
+    @Test
+    fun testOkWithOnlyText() {
+        val content = "TextMessage"
+        val result = CallToolResult.Companion.ok(content)
+
+        assertEquals(1, result.content.size)
+        assertEquals(content, (result.content[0] as TextContent).text)
+        assertFalse(result.isError == true)
+        assertEquals(EmptyJsonObject, result._meta)
+    }
+
+    @Test
+    fun testOkWithMeta() {
+        val content = "TextMessageWithMeta"
+        val meta = buildJsonObject {
+            put("key1", JsonPrimitive("value1"))
+            put("key2", JsonPrimitive(42))
+        }
+        val result = CallToolResult.Companion.ok(content, meta)
+
+        assertEquals(1, result.content.size)
+        assertEquals(content, (result.content[0] as TextContent).text)
+        assertFalse(result.isError == true)
+        assertEquals(meta, result._meta)
+    }
+
+    @Test
+    fun testErrorWithOnlyText() {
+        val content = "ErrorMessage"
+        val result = CallToolResult.Companion.error(content)
+
+        assertEquals(1, result.content.size)
+        assertEquals(content, (result.content[0] as TextContent).text)
+        assertTrue(result.isError == true)
+        assertEquals(EmptyJsonObject, result._meta)
+    }
+
+    @Test
+    fun testErrorWithMeta() {
+        val content = "ErrorMessageWithMeta"
+        val meta = buildJsonObject {
+            put("errorCode", JsonPrimitive(404))
+            put("errorDetail", JsonPrimitive("资源未找到"))
+        }
+        val result = CallToolResult.Companion.error(content, meta)
+
+        assertEquals(1, result.content.size)
+        assertEquals(content, (result.content[0] as TextContent).text)
+        assertTrue(result.isError == true)
+        assertEquals(meta, result._meta)
+    }
+}
+