diff --git a/scripts/bench-web-fetch.ts b/scripts/bench-web-fetch.ts
index 132fc1a5c310..1ed2b19241ec 100644
--- a/scripts/bench-web-fetch.ts
+++ b/scripts/bench-web-fetch.ts
@@ -7,7 +7,7 @@ import { createWebFetchTool } from "../src/agents/tools/web-fetch.js";
 import type { OpenClawConfig } from "../src/config/types.openclaw.js";
 import type { LookupFn } from "../src/infra/net/ssrf.js";
 import { extractReadableContent } from "../src/web-fetch/content-extractors.runtime.js";
-import { stripLeadingPackageManagerSeparator } from "./lib/arg-utils.mts";
+import * as cliArgs from "./lib/arg-utils.mts";
 
 type BenchmarkCaseId =
   | "tool-create"
@@ -68,8 +68,7 @@ const ALL_CASE_IDS = [
   "extract-basic-shell",
 ] as const satisfies readonly BenchmarkCaseId[];
 
-const BOOLEAN_FLAGS = new Set(["--help", "-h", "--json"]);
-const VALUE_FLAGS = new Set(["--case", "--output", "--runs", "--warmup"]);
+const SPLIT_VALUE_FLAG_OPTIONS = { allowInline: false, rejectShortOptions: true } as const;
 
 class CliArgumentError extends Error {
   override name = "CliArgumentError";
@@ -125,71 +124,7 @@ const toolConfig: OpenClawConfig = {
   },
 };
 
-function validateArgs(args: string[]): void {
-  const seenSingularValueFlags = new Set<string>();
-  for (let index = 0; index < args.length; index += 1) {
-    const arg = args[index] ?? "";
-    if (BOOLEAN_FLAGS.has(arg)) {
-      continue;
-    }
-    if (VALUE_FLAGS.has(arg)) {
-      if (arg !== "--case") {
-        if (seenSingularValueFlags.has(arg)) {
-          throw new CliArgumentError(`${arg} was provided more than once`);
-        }
-        seenSingularValueFlags.add(arg);
-      }
-      const value = args[index + 1];
-      if (!value || value.startsWith("-")) {
-        throw new CliArgumentError(`${arg} requires a value`);
-      }
-      index += 1;
-      continue;
-    }
-    throw new CliArgumentError(`Unknown argument: ${arg}`);
-  }
-}
-
-function parsePositiveInteger(flag: string, fallback: number, args: string[]): number {
-  const index = args.indexOf(flag);
-  if (index === -1) {
-    return fallback;
-  }
-  const raw = args[index + 1];
-  if (!/^\d+$/u.test(raw ?? "")) {
-    throw new CliArgumentError(`${flag} must be a positive integer`);
-  }
-  const value = Number(raw);
-  if (!Number.isSafeInteger(value) || value <= 0) {
-    throw new CliArgumentError(`${flag} must be a positive integer`);
-  }
-  return value;
-}
-
-function parseNonNegativeInteger(flag: string, fallback: number, args: string[]): number {
-  const index = args.indexOf(flag);
-  if (index === -1) {
-    return fallback;
-  }
-  const raw = args[index + 1];
-  if (!/^\d+$/u.test(raw ?? "")) {
-    throw new CliArgumentError(`${flag} must be a non-negative integer`);
-  }
-  const value = Number(raw);
-  if (!Number.isSafeInteger(value) || value < 0) {
-    throw new CliArgumentError(`${flag} must be a non-negative integer`);
-  }
-  return value;
-}
-
-function parseCases(args: string[]): BenchmarkCaseId[] {
-  const requested: string[] = [];
-  for (let index = 0; index < args.length; index += 1) {
-    if (args[index] === "--case") {
-      requested.push(args[index + 1] ?? "");
-      index += 1;
-    }
-  }
+function parseCases(requested: string[]): BenchmarkCaseId[] {
   if (requested.length === 0 || requested.includes("all")) {
     return [...ALL_CASE_IDS];
   }
@@ -204,21 +139,51 @@ function parseCases(args: string[]): BenchmarkCaseId[] {
   return requested as BenchmarkCaseId[];
 }
 
-function parseFlagValue(flag: string, args: string[]): string | undefined {
-  const index = args.indexOf(flag);
-  return index === -1 ? undefined : args[index + 1];
+function parseBenchmarkCount(raw: string, flag: string, minimum: 0 | 1): number {
+  const parsed = cliArgs.classifyBoundedUnsignedDecimal(raw, minimum, Number.MAX_SAFE_INTEGER);
+  if (parsed.kind === "value") {
+    return parsed.value;
+  }
+  const kind = minimum === 0 ? "non-negative" : "positive";
+  throw new CliArgumentError(`${flag} must be a ${kind} integer`);
 }
 
 function parseOptions(args = process.argv.slice(2)): Options {
-  const normalizedArgs = stripLeadingPackageManagerSeparator(args);
-  validateArgs(normalizedArgs);
-  return {
-    cases: parseCases(normalizedArgs),
-    json: normalizedArgs.includes("--json"),
-    output: parseFlagValue("--output", normalizedArgs),
-    runs: parsePositiveInteger("--runs", 20, normalizedArgs),
-    warmup: parseNonNegativeInteger("--warmup", 3, normalizedArgs),
-  };
+  const normalizedArgs = cliArgs.stripLeadingPackageManagerSeparator(args);
+  try {
+    const parsed = cliArgs.parseFlagArgs(
+      normalizedArgs,
+      {
+        cases: [] as string[],
+        json: false,
+        output: undefined as string | undefined,
+        runs: "20",
+        warmup: "3",
+      },
+      [
+        cliArgs.stringListFlag("--case", "cases", SPLIT_VALUE_FLAG_OPTIONS),
+        cliArgs.stringFlag("--output", "output", SPLIT_VALUE_FLAG_OPTIONS),
+        cliArgs.stringFlag("--runs", "runs", SPLIT_VALUE_FLAG_OPTIONS),
+        cliArgs.stringFlag("--warmup", "warmup", SPLIT_VALUE_FLAG_OPTIONS),
+        cliArgs.booleanFlag("--json", "json", true, { repeatable: true }),
+      ],
+      {
+        ignoreDoubleDash: false,
+        onUnhandledArg(arg) {
+          throw new CliArgumentError(`Unknown argument: ${arg}`);
+        },
+      },
+    );
+    return {
+      cases: parseCases(parsed.cases),
+      json: parsed.json,
+      output: parsed.output,
+      runs: parseBenchmarkCount(parsed.runs, "--runs", 1),
+      warmup: parseBenchmarkCount(parsed.warmup, "--warmup", 0),
+    };
+  } catch (error) {
+    throw new CliArgumentError(error instanceof Error ? error.message : String(error));
+  }
 }
 
 function printUsage(): void {