diff --git a/packages/cli/src/commands/image/edit.ts b/packages/cli/src/commands/image/edit.ts
index a8bf39b..42f5d14 100644
--- a/packages/cli/src/commands/image/edit.ts
+++ b/packages/cli/src/commands/image/edit.ts
@@ -24,6 +24,10 @@ import { promptText, failIfMissing } from "../../output/prompt.ts";
 import { emitResult, emitBare } from "../../output/output.ts";
 import { resolveImageSize } from "../../utils/image-size.ts";
 import { join } from "path";
+import {
+  BOOL_FLAG_PROMPT_EXTEND_CLI_TRUE,
+  BOOL_FLAG_WATERMARK,
+} from "../../utils/flag-descriptions.ts";
 
 export default defineCommand({
   name: "image edit",
@@ -51,11 +55,11 @@ export default defineCommand({
     },
     {
       flag: "--prompt-extend <bool>",
-      description: "Enable prompt extend (true/false). Default: true.",
+      description: BOOL_FLAG_PROMPT_EXTEND_CLI_TRUE,
     },
     {
       flag: "--watermark <bool>",
-      description: "Enable watermark (true/false). Default: true.",
+      description: BOOL_FLAG_WATERMARK,
     },
     { flag: "--out-dir <dir>", description: "Download images to directory" },
     { flag: "--out-prefix <prefix>", description: "Filename prefix (default: edited)" },
diff --git a/packages/cli/src/commands/image/generate.ts b/packages/cli/src/commands/image/generate.ts
index 9189ba2..1b89c90 100644
--- a/packages/cli/src/commands/image/generate.ts
+++ b/packages/cli/src/commands/image/generate.ts
@@ -26,6 +26,10 @@ import { runConcurrent, downloadParallel, getConcurrency } from "../../utils/con
 import { promptText, failIfMissing } from "../../output/prompt.ts";
 import { emitResult, emitBare } from "../../output/output.ts";
 import { resolveImageSize } from "../../utils/image-size.ts";
+import {
+  BOOL_FLAG_PROMPT_EXTEND_IMAGE_GENERATE,
+  BOOL_FLAG_WATERMARK,
+} from "../../utils/flag-descriptions.ts";
 
 import { join } from "path";
 
@@ -60,12 +64,11 @@ export default defineCommand({
     },
     {
       flag: "--prompt-extend <bool>",
-      description:
-        "Enable prompt extend (true/false). Default: true for qwen-image sync models; omit for async.",
+      description: BOOL_FLAG_PROMPT_EXTEND_IMAGE_GENERATE,
     },
     {
       flag: "--watermark <bool>",
-      description: "Enable watermark (true/false). Default: true.",
+      description: BOOL_FLAG_WATERMARK,
     },
     {
       flag: "--no-wait",
diff --git a/packages/cli/src/commands/video/edit.ts b/packages/cli/src/commands/video/edit.ts
index 9c69533..9ec8948 100644
--- a/packages/cli/src/commands/video/edit.ts
+++ b/packages/cli/src/commands/video/edit.ts
@@ -22,6 +22,10 @@ import { poll } from "../../utils/polling.ts";
 import { downloadFile, formatBytes } from "../../utils/download.ts";
 import { promptText, failIfMissing } from "../../output/prompt.ts";
 import { emitResult, emitBare } from "../../output/output.ts";
+import {
+  BOOL_FLAG_PROMPT_EXTEND_API_DEFAULT,
+  BOOL_FLAG_WATERMARK,
+} from "../../utils/flag-descriptions.ts";
 
 export default defineCommand({
   name: "video edit",
@@ -55,11 +59,11 @@ export default defineCommand({
     },
     {
       flag: "--prompt-extend <bool>",
-      description: "Enable prompt extend (true/false). Omit to use API default.",
+      description: BOOL_FLAG_PROMPT_EXTEND_API_DEFAULT,
     },
     {
       flag: "--watermark <bool>",
-      description: "Enable watermark (true/false). Default: true.",
+      description: BOOL_FLAG_WATERMARK,
     },
     { flag: "--seed <n>", description: "Random seed for reproducible generation", type: "number" },
     { flag: "--download <path>", description: "Save video to file on completion" },
diff --git a/packages/cli/src/commands/video/generate.ts b/packages/cli/src/commands/video/generate.ts
index cfd2bc3..4fcab06 100644
--- a/packages/cli/src/commands/video/generate.ts
+++ b/packages/cli/src/commands/video/generate.ts
@@ -23,6 +23,10 @@ import { downloadFile, formatBytes } from "../../utils/download.ts";
 import { runConcurrent, getConcurrency } from "../../utils/concurrent.ts";
 import { promptText, failIfMissing } from "../../output/prompt.ts";
 import { emitResult, emitBare } from "../../output/output.ts";
+import {
+  BOOL_FLAG_PROMPT_EXTEND_API_DEFAULT,
+  BOOL_FLAG_WATERMARK,
+} from "../../utils/flag-descriptions.ts";
 
 // Normalize shorthand resolution (720P, 1080P) to pixel format for video generation models
 const RESOLUTION_SHORTCUTS: Record<string, string> = {
@@ -62,11 +66,11 @@ export default defineCommand({
     },
     {
       flag: "--prompt-extend <bool>",
-      description: "Enable prompt extend (true/false). Omit to use API default.",
+      description: BOOL_FLAG_PROMPT_EXTEND_API_DEFAULT,
     },
     {
       flag: "--watermark <bool>",
-      description: "Enable watermark (true/false). Default: true.",
+      description: BOOL_FLAG_WATERMARK,
     },
     { flag: "--seed <n>", description: "Random seed for reproducible generation", type: "number" },
     { flag: "--download <path>", description: "Save video to file on completion" },
diff --git a/packages/cli/src/commands/video/ref.ts b/packages/cli/src/commands/video/ref.ts
index 458e0df..ecf185f 100644
--- a/packages/cli/src/commands/video/ref.ts
+++ b/packages/cli/src/commands/video/ref.ts
@@ -22,6 +22,10 @@ import { poll } from "../../utils/polling.ts";
 import { downloadFile, formatBytes } from "../../utils/download.ts";
 import { promptText, failIfMissing } from "../../output/prompt.ts";
 import { emitResult, emitBare } from "../../output/output.ts";
+import {
+  BOOL_FLAG_PROMPT_EXTEND_API_DEFAULT,
+  BOOL_FLAG_WATERMARK,
+} from "../../utils/flag-descriptions.ts";
 
 export default defineCommand({
   name: "video ref",
@@ -65,11 +69,11 @@ export default defineCommand({
     },
     {
       flag: "--prompt-extend <bool>",
-      description: "Enable prompt extend (true/false). Omit to use API default.",
+      description: BOOL_FLAG_PROMPT_EXTEND_API_DEFAULT,
     },
     {
       flag: "--watermark <bool>",
-      description: "Enable watermark (true/false). Default: true.",
+      description: BOOL_FLAG_WATERMARK,
     },
     { flag: "--seed <n>", description: "Random seed for reproducible generation", type: "number" },
     { flag: "--download <path>", description: "Save video to file on completion" },
diff --git a/packages/cli/src/utils/flag-descriptions.ts b/packages/cli/src/utils/flag-descriptions.ts
new file mode 100644
index 0000000..9c63031
--- /dev/null
+++ b/packages/cli/src/utils/flag-descriptions.ts
@@ -0,0 +1,16 @@
+/** Shared --foo <bool> help text; keep wording consistent across commands. */
+
+export const BOOL_FLAG_WATERMARK =
+  "Enable watermark (true/false). Default: true. Omit to use API default.";
+
+/** CLI sends prompt_extend=true when flag omitted (qwen-image edit, etc.). */
+export const BOOL_FLAG_PROMPT_EXTEND_CLI_TRUE =
+  "Enable prompt extend (true/false). Default: true. Omit to use API default.";
+
+/** Sync qwen-image defaults on; async models omit the field unless flag is set. */
+export const BOOL_FLAG_PROMPT_EXTEND_IMAGE_GENERATE =
+  "Enable prompt extend (true/false). Default: true for qwen-image sync. Omit to use API default.";
+
+/** CLI omits prompt_extend in the request when flag is unset (video commands). */
+export const BOOL_FLAG_PROMPT_EXTEND_API_DEFAULT =
+  "Enable prompt extend (true/false). Default: API default. Omit to use API default.";
diff --git a/packages/cli/tests/args.test.ts b/packages/cli/tests/args.test.ts
index 1a72036..890deeb 100644
--- a/packages/cli/tests/args.test.ts
+++ b/packages/cli/tests/args.test.ts
@@ -1,11 +1,12 @@
 import { expect, test } from "vite-plus/test";
 import { ExitCode, GLOBAL_OPTIONS } from "bailian-cli-core";
 import { parseFlags } from "../src/args.ts";
+import { BOOL_FLAG_WATERMARK } from "../src/utils/flag-descriptions.ts";
 
 const IMAGE_GENERATE_OPTIONS = [
   { flag: "--prompt <text>", description: "Image description", required: true },
   { flag: "--model <model>", description: "Model ID" },
-  { flag: "--watermark <bool>", description: "Enable watermark (true/false). Default: true." },
+  { flag: "--watermark <bool>", description: BOOL_FLAG_WATERMARK },
 ];
 
 test("parseFlags rejects unknown long flags", () => {