diff --git a/extensions/browser/src/browser/routes/agent.snapshot.plan.test.ts b/extensions/browser/src/browser/routes/agent.snapshot.plan.test.ts
index e40c697a22f..7d421d88bf5 100644
--- a/extensions/browser/src/browser/routes/agent.snapshot.plan.test.ts
+++ b/extensions/browser/src/browser/routes/agent.snapshot.plan.test.ts
@@ -1,5 +1,6 @@
 import { describe, expect, it } from "vitest";
 import type { ResolvedBrowserProfile } from "../config.js";
+import { DEFAULT_AI_SNAPSHOT_MAX_CHARS } from "../constants.js";
 import { resolveSnapshotPlan } from "./agent.snapshot.plan.js";
 
 function profile(driver: "existing-session" | "openclaw"): ResolvedBrowserProfile {
@@ -68,6 +69,70 @@ describe("resolveSnapshotPlan", () => {
     expect(plan.timeoutMs).toBe(2_147_483_647);
   });
 
+  it("parses snapshot numeric query options as strict integers", () => {
+    const plan = resolveSnapshotPlan({
+      profile: profile("openclaw"),
+      query: {
+        limit: "25",
+        maxChars: "5000",
+        depth: "2",
+        timeoutMs: "12345",
+      },
+      hasPlaywright: true,
+    });
+
+    expect(plan.limit).toBe(25);
+    expect(plan.resolvedMaxChars).toBe(5000);
+    expect(plan.depth).toBe(2);
+    expect(plan.timeoutMs).toBe(12345);
+  });
+
+  it("accepts structured numeric snapshot query options from proxy dispatch", () => {
+    const plan = resolveSnapshotPlan({
+      profile: profile("openclaw"),
+      query: {
+        limit: 25,
+        maxChars: 5000,
+        depth: 2,
+        timeoutMs: 12345,
+      },
+      hasPlaywright: true,
+    });
+
+    expect(plan.limit).toBe(25);
+    expect(plan.resolvedMaxChars).toBe(5000);
+    expect(plan.depth).toBe(2);
+    expect(plan.timeoutMs).toBe(12345);
+  });
+
+  it("rejects loose snapshot numeric query tokens", () => {
+    const plan = resolveSnapshotPlan({
+      profile: profile("openclaw"),
+      query: {
+        limit: "0x10",
+        maxChars: "1.5",
+        depth: "1e0",
+        timeoutMs: "1000ms",
+      },
+      hasPlaywright: true,
+    });
+
+    expect(plan.limit).toBeUndefined();
+    expect(plan.resolvedMaxChars).toBe(DEFAULT_AI_SNAPSHOT_MAX_CHARS);
+    expect(plan.depth).toBeUndefined();
+    expect(plan.timeoutMs).toBeUndefined();
+  });
+
+  it("keeps maxChars zero as an explicit uncapped snapshot request", () => {
+    const plan = resolveSnapshotPlan({
+      profile: profile("openclaw"),
+      query: { maxChars: "0" },
+      hasPlaywright: true,
+    });
+
+    expect(plan.resolvedMaxChars).toBeUndefined();
+  });
+
   it("ignores non-positive timeoutMs values", () => {
     expect(
       resolveSnapshotPlan({
diff --git a/extensions/browser/src/browser/routes/agent.snapshot.plan.ts b/extensions/browser/src/browser/routes/agent.snapshot.plan.ts
index 31baea05e74..333e16bca69 100644
--- a/extensions/browser/src/browser/routes/agent.snapshot.plan.ts
+++ b/extensions/browser/src/browser/routes/agent.snapshot.plan.ts
@@ -1,7 +1,8 @@
 import {
-  normalizeOptionalString,
-  readStringValue,
-} from "openclaw/plugin-sdk/string-coerce-runtime";
+  parseStrictNonNegativeInteger,
+  parseStrictPositiveInteger,
+} from "openclaw/plugin-sdk/number-runtime";
+import { normalizeOptionalString } from "openclaw/plugin-sdk/string-coerce-runtime";
 import type { ResolvedBrowserProfile } from "../config.js";
 import {
   DEFAULT_AI_SNAPSHOT_EFFICIENT_DEPTH,
@@ -14,7 +15,7 @@ import {
   shouldUsePlaywrightForScreenshot,
 } from "../profile-capabilities.js";
 import { normalizeBrowserTimerDelayMs } from "../timer-delay.js";
-import { toBoolean, toNumber, toStringOrEmpty } from "./utils.js";
+import { toBoolean, toStringOrEmpty } from "./utils.js";
 
 type BrowserSnapshotPlan = {
   format: "ai" | "aria";
@@ -49,25 +50,25 @@ export function resolveSnapshotPlan(params: {
     explicitFormat,
     mode,
   });
-  const limitRaw = readStringValue(params.query.limit);
+  const limit = parseStrictPositiveInteger(params.query.limit);
   const hasMaxChars = Object.hasOwn(params.query, "maxChars");
-  const maxCharsRaw = readStringValue(params.query.maxChars);
-  const limit = Number.isFinite(Number(limitRaw)) ? Number(limitRaw) : undefined;
-  const maxChars =
-    Number.isFinite(Number(maxCharsRaw)) && Number(maxCharsRaw) > 0
-      ? Math.floor(Number(maxCharsRaw))
-      : undefined;
+  const maxCharsRaw = parseStrictNonNegativeInteger(params.query.maxChars);
+  const maxChars = maxCharsRaw !== undefined && maxCharsRaw > 0 ? maxCharsRaw : undefined;
   const resolvedMaxChars =
     format === "ai"
       ? hasMaxChars
-        ? maxChars
+        ? maxCharsRaw === undefined
+          ? mode === "efficient"
+            ? DEFAULT_AI_SNAPSHOT_EFFICIENT_MAX_CHARS
+            : DEFAULT_AI_SNAPSHOT_MAX_CHARS
+          : maxChars
         : mode === "efficient"
           ? DEFAULT_AI_SNAPSHOT_EFFICIENT_MAX_CHARS
           : DEFAULT_AI_SNAPSHOT_MAX_CHARS
       : undefined;
   const interactiveRaw = toBoolean(params.query.interactive);
   const compactRaw = toBoolean(params.query.compact);
-  const depthRaw = toNumber(params.query.depth);
+  const depthRaw = parseStrictNonNegativeInteger(params.query.depth);
   const refsModeRaw = toStringOrEmpty(params.query.refs).trim();
   const refsMode: "aria" | "role" | undefined =
     refsModeRaw === "aria" ? "aria" : refsModeRaw === "role" ? "role" : undefined;
@@ -77,11 +78,9 @@ export function resolveSnapshotPlan(params: {
     depthRaw ?? (mode === "efficient" ? DEFAULT_AI_SNAPSHOT_EFFICIENT_DEPTH : undefined);
   const selectorValue = normalizeOptionalString(toStringOrEmpty(params.query.selector));
   const frameSelectorValue = normalizeOptionalString(toStringOrEmpty(params.query.frame));
-  const timeoutMsRaw = toNumber(params.query.timeoutMs);
+  const timeoutMsRaw = parseStrictPositiveInteger(params.query.timeoutMs);
   const timeoutMs =
-    timeoutMsRaw !== undefined && Number.isFinite(timeoutMsRaw) && timeoutMsRaw > 0
-      ? normalizeBrowserTimerDelayMs(timeoutMsRaw)
-      : undefined;
+    timeoutMsRaw !== undefined ? normalizeBrowserTimerDelayMs(timeoutMsRaw) : undefined;
 
   return {
     format,