@@ -37,6 +37,7 @@ import { join } from "path";
 import { BOOL_FLAG_PROMPT_EXTEND_CLI_TRUE, BOOL_FLAG_WATERMARK } from "bailian-cli-runtime";
 import {
   isAutoModel,
+  assertAutoMcpAvailable,
   assertMcpCompatible,
   withAigcMcpSession,
   resolveAutoImageInput,
@@ -371,6 +372,7 @@ async function handleAutoMcpMode(
   rawImages: string[],
   format: OutputFormat,
 ): Promise<void> {
+  assertAutoMcpAvailable(client, localize);
   assertMcpCompatible("imageEdit", flags, localize);
 
   // bailian_image_edit takes a single source image; bailian_image_fusion is out
 
@@ -34,7 +34,9 @@ import { resolveImageSize } from "bailian-cli-runtime";
 import { BOOL_FLAG_PROMPT_EXTEND_IMAGE_GENERATE, BOOL_FLAG_WATERMARK } from "bailian-cli-runtime";
 import {
   isAutoModel,
+  assertAutoMcpAvailable,
   assertMcpCompatible,
+  resolveAutoImageSize,
   withAigcMcpSession,
   type Localize,
 } from "../shared/aigc-mcp.ts";
@@ -278,12 +280,13 @@ async function handleAutoMcpMode(
   flags: GenerateFlags,
   format: string,
 ): Promise<void> {
+  assertAutoMcpAvailable(client, localize);
   assertMcpCompatible("imageGen", flags, localize);
 
   const concurrent = getConcurrency(flags);
   const args = buildImageGenArgs({
     prompt: flags.prompt,
-    size: flags.size || undefined,
+    size: resolveAutoImageSize(flags.size, localize),
     n: flags.n,
     negativePrompt: flags.negativePrompt || undefined,
     promptExtend: flags.promptExtend,
 
@@ -20,7 +20,10 @@ import {
   parseAigcToolResult,
   imageFileToDataUri,
   audioFileToDataUri,
+  isMcpTtsVoice,
+  MCP_TTS_VOICES,
   MCP_CALL_SERVICE,
+  resolveMcpImageSize,
   type Client,
   type LocalizedText,
   type McpConnectedClient,
@@ -199,6 +202,70 @@ export function mcpSingleImageOnlyError(localize: Localize): BailianError {
   return new BailianError(message, ExitCode.USAGE, hint);
 }
 
+// ---- Connection applicability gate ----
+
+/**
+ * Reject `auto` mode up front when the effective connection cannot reach the
+ * Bailian AIGC MCP servers. Both Token Plan shapes were verified against the
+ * live gateways: the token-plan endpoint has no `/api/v1/mcps` route at all
+ * (bare 404, empty body) and plan keys (`sk-sp-`) are refused on the standard
+ * MCP path (401 InvalidApiKey). Neither server response is self-explanatory,
+ * and this applicability fact is authoritative on the client side, so it is
+ * raised before any request instead of passing the opaque error through.
+ */
+export function assertAutoMcpAvailable(client: Client, localize: Localize): void {
+  if (!client.usesTokenPlanConnection()) return;
+  const message = localize({
+    "en-US":
+      "The current model (auto) routes generation through Bailian MCP, which the Token Plan connection (endpoint or API key) does not provide.",
+    "zh-CN": "当前模型（auto）经百炼 MCP 路由生成，Token Plan 连接（端点或 API Key）不提供该能力。",
+  });
+  const hint = localize({
+    "en-US":
+      "Switch to a config profile with a standard DashScope API key, or pass --model <id> to keep using Token Plan models.",
+    "zh-CN":
+      "请切换到含标准 DashScope API Key 的配置，或传入 --model <id> 继续使用 Token Plan 模型。",
+  });
+  throw new BailianError(message, ExitCode.USAGE, hint);
+}
+
+// ---- MCP input value gates (auto mode) ----
+
+/**
+ * Resolve an `auto`-mode `--size` for MCP image generation: ratios map to the
+ * server's pixel presets and pixel input passes through; values MCP cannot
+ * accept are rejected up front with the unsupported-parameter USAGE error.
+ */
+export function resolveAutoImageSize(
+  size: string | undefined,
+  localize: Localize,
+): string | undefined {
+  if (size === undefined) return undefined;
+  const mapped = resolveMcpImageSize(size);
+  if (mapped === undefined) {
+    throw mcpUnsupportedError(localize, [`--size ${size}`]);
+  }
+  return mapped;
+}
+
+/**
+ * Reject `auto`-mode TTS voices outside the MCP enum before any request: REST
+ * voice IDs (e.g. `longxiaochun_v3`) are not accepted by `bailian_tts`.
+ */
+export function assertMcpTtsVoice(voice: string, localize: Localize): void {
+  if (isMcpTtsVoice(voice)) return;
+  const list = MCP_TTS_VOICES.join(", ");
+  const message = localize({
+    "en-US": `The current model (auto) does not support voice "${voice}". MCP TTS voices: ${list}.`,
+    "zh-CN": `当前模型（auto）不支持音色 "${voice}"。MCP 可选音色：${list}。`,
+  });
+  const hint = localize({
+    "en-US": "Pass one of the listed MCP voices, or use --model <id> for the REST system voices.",
+    "zh-CN": "请传入所列 MCP 音色，或使用 --model <id> 改用 REST 系统音色。",
+  });
+  throw new BailianError(message, ExitCode.USAGE, hint);
+}
+
 // ---- Local file input (auto mode inlines files as base64 data URIs) ----
 
 /**
 
@@ -36,6 +36,7 @@ import { poll } from "bailian-cli-runtime";
 import { emitResult, emitBare } from "bailian-cli-runtime";
 import {
   isAutoModel,
+  assertAutoMcpAvailable,
   assertMcpCompatible,
   withAigcMcpSession,
   resolveAutoAudioInput,
@@ -351,6 +352,7 @@ async function handleAutoMcpMode(
   rawUrls: string[],
   format: OutputFormat,
 ): Promise<void> {
+  assertAutoMcpAvailable(client, localize);
   assertMcpCompatible("asr", flags, localize);
 
   if (rawUrls.length === 0) {
 
@@ -31,7 +31,9 @@ import { emitResult, emitBare } from "bailian-cli-runtime";
 import { VOICE_TTS_PAGE } from "bailian-cli-runtime";
 import {
   isAutoModel,
+  assertAutoMcpAvailable,
   assertMcpCompatible,
+  assertMcpTtsVoice,
   withAigcMcpSession,
   type Localize,
 } from "../shared/aigc-mcp.ts";
@@ -484,6 +486,7 @@ async function handleAutoMcpMode(
   flags: SynthesizeFlags,
   format: OutputFormat,
 ): Promise<void> {
+  assertAutoMcpAvailable(client, localize);
   assertMcpCompatible("tts", flags, localize);
 
   // Same text precedence as REST: --text, else --text-file.
@@ -496,9 +499,10 @@ async function handleAutoMcpMode(
       throw new BailianError(`Cannot read text file: ${filePath}`, ExitCode.USAGE);
     }
   }
-  // Voice is passed through verbatim (validate enforces its presence); the MCP
-  // server validates it against its own voice enum.
+  // Voice must be one of the MCP enum values; REST voice IDs are rejected up
+  // front so dry-run never previews a request the server cannot accept.
   const voice = flags.voice as string;
+  assertMcpTtsVoice(voice, localize);
   const args = buildTtsArgs({ text, voice });
 
   if (settings.dryRun) {
 
@@ -34,10 +34,12 @@ import { BOOL_FLAG_PROMPT_EXTEND_API_DEFAULT, BOOL_FLAG_WATERMARK } from "bailia
 import { PRIME_FLAGS, resolvePrimeEndpoint, validatePrimeFlags } from "../shared/prime.ts";
 import {
   isAutoModel,
+  assertAutoMcpAvailable,
   assertMcpCompatible,
   withAigcMcpSession,
   resolveAutoImageInput,
   type AigcMcpCallTool,
+  type Localize,
 } from "../shared/aigc-mcp.ts";
 
 export default defineCommand({
@@ -214,6 +216,7 @@ export default defineCommand({
 
     // auto model → official AIGC MCP (VideoGenerate); specific models keep the REST path.
     if (isAutoModel(resolvedModel)) {
+      assertAutoMcpAvailable(ctx.client, ctx.localize);
       const imageInput = flags.image;
       assertMcpCompatible(
         imageInput !== undefined ? "videoImageToVideo" : "videoTextToVideo",
@@ -273,7 +276,9 @@ export default defineCommand({
             "tasks",
           );
           return Promise.all(
-            taskIds.map((taskId) => pollMcpVideoTask(callTool, taskId, settings, pollInterval)),
+            taskIds.map((taskId) =>
+              pollMcpVideoTask(callTool, taskId, settings, pollInterval, ctx.localize),
+            ),
           );
         },
       );
@@ -519,6 +524,14 @@ export default defineCommand({
   },
 });
 
+/** Supplementary context for a failed MCP video task (server message is primary). */
+function videoTaskIdHint(localize: Localize, taskId: string): string {
+  return localize({
+    "en-US": `The failed video task id is ${taskId}.`,
+    "zh-CN": `失败的视频任务 ID 为 ${taskId}。`,
+  });
+}
+
 /**
  * Poll a video task to completion over MCP `bailian_text_to_video_fetch_result`.
  * Mirrors the REST `poll` UX (spinner + status), but the transport is a repeated
@@ -529,6 +542,7 @@ async function pollMcpVideoTask(
   taskId: string,
   settings: Settings,
   pollInterval: number,
+  localize: Localize,
 ): Promise<{ taskId: string; videoUrl: string }> {
   const deadline = Date.now() + settings.timeout * 1000;
   const spinner = createSpinner("Polling...");
@@ -554,6 +568,12 @@ async function pollMcpVideoTask(
 
       if (result.taskStatus === "FAILED") {
         spinner.stop("Failed.");
+        // Pass the server's failure reason through verbatim (AGENTS.md §3);
+        // the task id stays as supplementary context in the hint.
+        const serverReason = result.message ?? result.code;
+        if (serverReason) {
+          throw new BailianError(serverReason, ExitCode.GENERAL, videoTaskIdHint(localize, taskId));
+        }
         throw new BailianError(`Video task failed: ${taskId}`, ExitCode.GENERAL);
       }
 
 
@@ -1,11 +1,14 @@
 import { describe, expect, test } from "vite-plus/test";
-import { BailianError, ExitCode } from "bailian-cli-core";
+import { BailianError, ExitCode, type Client } from "bailian-cli-core";
 import {
   AUTO_MODEL,
+  assertAutoMcpAvailable,
   assertMcpCompatible,
+  assertMcpTtsVoice,
   isAutoModel,
   mcpSingleImageOnlyError,
   mcpUnsupportedError,
+  resolveAutoImageSize,
   type AigcMcpOperation,
   type Localize,
 } from "../src/commands/shared/aigc-mcp.ts";
@@ -147,3 +150,54 @@ describe("error message builders", () => {
     expect(singleImageError.message).toContain("single image");
   });
 });
+
+describe("assertAutoMcpAvailable rejects Token Plan connections", () => {
+  /** Minimal Client stub: only the accessor the applicability gate reads. */
+  function stubClient(tokenPlanConnection: boolean): Client {
+    return {
+      usesTokenPlanConnection: () => tokenPlanConnection,
+    } as unknown as Client;
+  }
+
+  test("Token Plan connection throws USAGE with an actionable hint (en-US)", () => {
+    const error = captureUsage(() => assertAutoMcpAvailable(stubClient(true), enUS));
+    expect(error.message).toContain("Token Plan");
+    expect(error.hint).toContain("--model");
+  });
+
+  test("zh-CN localization mentions Token Plan and the model fallback", () => {
+    const error = captureUsage(() => assertAutoMcpAvailable(stubClient(true), zhCN));
+    expect(error.message).toContain("Token Plan");
+    expect(error.hint).toContain("Token Plan 模型");
+  });
+
+  test("non-Token-Plan connection passes", () => {
+    expect(() => assertAutoMcpAvailable(stubClient(false), enUS)).not.toThrow();
+  });
+});
+
+describe("resolveAutoImageSize maps or rejects --size for MCP", () => {
+  test("ratios map to pixel presets and pixels pass through", () => {
+    expect(resolveAutoImageSize("16:9", enUS)).toBe("1664*928");
+    expect(resolveAutoImageSize("2048*2048", enUS)).toBe("2048*2048");
+    expect(resolveAutoImageSize(undefined, enUS)).toBeUndefined();
+  });
+
+  test("unmappable values throw the unsupported-parameter USAGE error", () => {
+    const error = captureUsage(() => resolveAutoImageSize("2:3", enUS));
+    expect(error.message).toContain("--size 2:3");
+  });
+});
+
+describe("assertMcpTtsVoice rejects REST voice IDs", () => {
+  test("enum voices pass", () => {
+    expect(() => assertMcpTtsVoice("温柔女声", enUS)).not.toThrow();
+  });
+
+  test("REST voice IDs throw USAGE listing the MCP enum", () => {
+    const error = captureUsage(() => assertMcpTtsVoice("longxiaochun_v3", enUS));
+    expect(error.message).toContain("longxiaochun_v3");
+    expect(error.message).toContain("温柔女声");
+    expect(error.hint).toContain("--model");
+  });
+});