diff --git a/src/agents/agent-scope.ts b/src/agents/agent-scope.ts
index 262c3bde5e5..affda75716b 100644
--- a/src/agents/agent-scope.ts
+++ b/src/agents/agent-scope.ts
@@ -11,7 +11,11 @@ import {
   parseAgentSessionKey,
   resolveAgentIdFromSessionKey,
 } from "../routing/session-key.js";
-import { readStringValue, resolvePrimaryStringValue } from "../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  readStringValue,
+  resolvePrimaryStringValue,
+} from "../shared/string-coerce.js";
 import { resolveUserPath } from "../utils.js";
 import { resolveEffectiveAgentSkillFilter } from "./skills/agent-filter.js";
 import { resolveDefaultAgentWorkspaceDir } from "./workspace.js";
@@ -105,11 +109,10 @@ export function resolveSessionAgentIds(params: {
   sessionAgentId: string;
 } {
   const defaultAgentId = resolveDefaultAgentId(params.config ?? {});
-  const explicitAgentIdRaw =
-    typeof params.agentId === "string" ? params.agentId.trim().toLowerCase() : "";
+  const explicitAgentIdRaw = normalizeLowercaseStringOrEmpty(params.agentId);
   const explicitAgentId = explicitAgentIdRaw ? normalizeAgentId(explicitAgentIdRaw) : null;
   const sessionKey = params.sessionKey?.trim();
-  const normalizedSessionKey = sessionKey ? sessionKey.toLowerCase() : undefined;
+  const normalizedSessionKey = sessionKey ? normalizeLowercaseStringOrEmpty(sessionKey) : undefined;
   const parsed = normalizedSessionKey ? parseAgentSessionKey(normalizedSessionKey) : null;
   const sessionAgentId =
     explicitAgentId ?? (parsed?.agentId ? normalizeAgentId(parsed.agentId) : defaultAgentId);
diff --git a/src/agents/identity-file.ts b/src/agents/identity-file.ts
index 5942589a2bf..0bbd47f3bf7 100644
--- a/src/agents/identity-file.ts
+++ b/src/agents/identity-file.ts
@@ -1,5 +1,6 @@
 import fs from "node:fs";
 import path from "node:path";
+import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";
 import { DEFAULT_IDENTITY_FILENAME } from "./workspace.js";
 
 export type AgentIdentityFile = {
@@ -26,8 +27,7 @@ function normalizeIdentityValue(value: string): string {
     normalized = normalized.slice(1, -1).trim();
   }
   normalized = normalized.replace(/[\u2013\u2014]/g, "-");
-  normalized = normalized.replace(/\s+/g, " ").toLowerCase();
-  return normalized;
+  return normalizeLowercaseStringOrEmpty(normalized.replace(/\s+/g, " "));
 }
 
 function isIdentityPlaceholder(value: string): boolean {
@@ -44,7 +44,9 @@ export function parseIdentityMarkdown(content: string): AgentIdentityFile {
     if (colonIndex === -1) {
       continue;
     }
-    const label = cleaned.slice(0, colonIndex).replace(/[*_]/g, "").trim().toLowerCase();
+    const label = normalizeLowercaseStringOrEmpty(
+      cleaned.slice(0, colonIndex).replace(/[*_]/g, ""),
+    );
     const value = cleaned
       .slice(colonIndex + 1)
       .replace(/^[*_]+|[*_]+$/g, "")
diff --git a/src/agents/pi-embedded-subscribe.handlers.tools.ts b/src/agents/pi-embedded-subscribe.handlers.tools.ts
index 17a7597c077..8bc47eff622 100644
--- a/src/agents/pi-embedded-subscribe.handlers.tools.ts
+++ b/src/agents/pi-embedded-subscribe.handlers.tools.ts
@@ -20,7 +20,7 @@ import type { ExecApprovalDecision } from "../infra/exec-approvals.js";
 import { splitMediaFromOutput } from "../media/parse.js";
 import { getGlobalHookRunner } from "../plugins/hook-runner-global.js";
 import type { PluginHookAfterToolCallEvent } from "../plugins/types.js";
-import { readStringValue } from "../shared/string-coerce.js";
+import { normalizeOptionalLowercaseString, readStringValue } from "../shared/string-coerce.js";
 import type { ApplyPatchSummary } from "./apply-patch.js";
 import type { ExecToolDetails } from "./bash-tools.exec-types.js";
 import { parseExecApprovalResultText } from "./exec-approval-result.js";
@@ -63,7 +63,7 @@ function isCronAddAction(args: unknown): boolean {
     return false;
   }
   const action = (args as Record<string, unknown>).action;
-  return typeof action === "string" && action.trim().toLowerCase() === "add";
+  return normalizeOptionalLowercaseString(action) === "add";
 }
 
 function buildToolCallSummary(toolName: string, args: unknown, meta?: string): ToolCallSummary {
@@ -180,7 +180,7 @@ function buildPatchSummaryText(summary: ApplyPatchSummary): string {
 }
 
 function extendExecMeta(toolName: string, args: unknown, meta?: string): string | undefined {
-  const normalized = toolName.trim().toLowerCase();
+  const normalized = normalizeOptionalLowercaseString(toolName);
   if (normalized !== "exec" && normalized !== "bash") {
     return meta;
   }
diff --git a/src/agents/pi-embedded-subscribe.tools.ts b/src/agents/pi-embedded-subscribe.tools.ts
index 02dbc37ba91..3306dcbe684 100644
--- a/src/agents/pi-embedded-subscribe.tools.ts
+++ b/src/agents/pi-embedded-subscribe.tools.ts
@@ -37,7 +37,7 @@ function normalizeToolErrorText(text: string): string | undefined {
 }
 
 function isErrorLikeStatus(status: string): boolean {
-  const normalized = status.trim().toLowerCase();
+  const normalized = normalizeOptionalLowercaseString(status);
   if (!normalized) {
     return false;
   }
diff --git a/src/agents/pi-tools.policy.ts b/src/agents/pi-tools.policy.ts
index cc6d2ef594f..9e9eef1a38a 100644
--- a/src/agents/pi-tools.policy.ts
+++ b/src/agents/pi-tools.policy.ts
@@ -8,6 +8,10 @@ import type { OpenClawConfig } from "../config/config.js";
 import { resolveChannelGroupToolsPolicy } from "../config/group-policy.js";
 import type { AgentToolsConfig } from "../config/types.tools.js";
 import { normalizeAgentId } from "../routing/session-key.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalLowercaseString,
+} from "../shared/string-coerce.js";
 import { normalizeMessageChannel } from "../utils/message-channel.js";
 import { resolveAgentConfig, resolveAgentIdFromSessionKey } from "./agent-scope.js";
 import type { AnyAgentTool } from "./pi-tools.types.js";
@@ -128,7 +132,7 @@ type ToolPolicyConfig = {
 };
 
 function normalizeProviderKey(value: string): string {
-  return value.trim().toLowerCase();
+  return normalizeLowercaseStringOrEmpty(value);
 }
 
 function resolveGroupContextFromSessionKey(sessionKey?: string | null): {
@@ -167,7 +171,7 @@ function resolveGroupContextFromSessionKey(sessionKey?: string | null): {
   if (!groupId) {
     return {};
   }
-  return { channel: channel.trim().toLowerCase(), groupId };
+  return { channel: normalizeLowercaseStringOrEmpty(channel), groupId };
 }
 
 function resolveProviderToolPolicy(params: {
@@ -195,7 +199,7 @@ function resolveProviderToolPolicy(params: {
   }
 
   const normalizedProvider = normalizeProviderKey(provider);
-  const rawModelId = params.modelId?.trim().toLowerCase();
+  const rawModelId = normalizeOptionalLowercaseString(params.modelId);
   const fullModelId =
     rawModelId && !rawModelId.includes("/") ? `${normalizedProvider}/${rawModelId}` : rawModelId;
 
diff --git a/src/agents/subagent-capabilities.ts b/src/agents/subagent-capabilities.ts
index cb9b386d97f..1da0f799222 100644
--- a/src/agents/subagent-capabilities.ts
+++ b/src/agents/subagent-capabilities.ts
@@ -2,6 +2,7 @@ import { DEFAULT_SUBAGENT_MAX_SPAWN_DEPTH } from "../config/agent-limits.js";
 import type { OpenClawConfig } from "../config/config.js";
 import { loadSessionStore, resolveStorePath } from "../config/sessions.js";
 import { isSubagentSessionKey, parseAgentSessionKey } from "../routing/session-key.js";
+import { normalizeOptionalLowercaseString } from "../shared/string-coerce.js";
 import { getSubagentDepthFromSessionStore } from "./subagent-depth.js";
 import { normalizeSubagentSessionKey } from "./subagent-session-key.js";
 
@@ -19,18 +20,12 @@ type SessionCapabilityEntry = {
 };
 
 function normalizeSubagentRole(value: unknown): SubagentSessionRole | undefined {
-  if (typeof value !== "string") {
-    return undefined;
-  }
-  const trimmed = value.trim().toLowerCase();
+  const trimmed = normalizeOptionalLowercaseString(value);
   return SUBAGENT_SESSION_ROLES.find((entry) => entry === trimmed);
 }
 
 function normalizeSubagentControlScope(value: unknown): SubagentControlScope | undefined {
-  if (typeof value !== "string") {
-    return undefined;
-  }
-  const trimmed = value.trim().toLowerCase();
+  const trimmed = normalizeOptionalLowercaseString(value);
   return SUBAGENT_CONTROL_SCOPES.find((entry) => entry === trimmed);
 }
 
diff --git a/src/agents/tool-display-common.ts b/src/agents/tool-display-common.ts
index 7025317444c..fcb280ddd8d 100644
--- a/src/agents/tool-display-common.ts
+++ b/src/agents/tool-display-common.ts
@@ -1,4 +1,7 @@
-import { normalizeOptionalString } from "../shared/string-coerce.js";
+import {
+  normalizeLowercaseStringOrEmpty,
+  normalizeOptionalString,
+} from "../shared/string-coerce.js";
 import { resolveExecDetail } from "./tool-display-exec.js";
 import { asRecord } from "./tool-display-record.js";
 
@@ -165,7 +168,7 @@ export function formatDetailKey(raw: string, overrides: Record<string, string> =
   }
   const cleaned = last.replace(/_/g, " ").replace(/-/g, " ");
   const spaced = cleaned.replace(/([a-z0-9])([A-Z])/g, "$1 $2");
-  return spaced.trim().toLowerCase() || last.toLowerCase();
+  return normalizeLowercaseStringOrEmpty(spaced) || normalizeLowercaseStringOrEmpty(last);
 }
 
 export function resolvePathArg(args: unknown): string | undefined {
diff --git a/src/agents/tool-display-exec-shell.ts b/src/agents/tool-display-exec-shell.ts
index 2de6eb477b8..742107e4abc 100644
--- a/src/agents/tool-display-exec-shell.ts
+++ b/src/agents/tool-display-exec-shell.ts
@@ -1,3 +1,5 @@
+import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";
+
 type PreambleResult = {
   command: string;
   chdirPath?: string;
@@ -82,7 +84,7 @@ export function binaryName(token: string | undefined): string | undefined {
   }
   const cleaned = stripOuterQuotes(token) ?? token;
   const segment = cleaned.split(/[/]/).at(-1) ?? cleaned;
-  return segment.trim().toLowerCase();
+  return normalizeLowercaseStringOrEmpty(segment);
 }
 
 export function optionValue(words: string[], names: string[]): string | undefined {
diff --git a/src/agents/tools/image-generate-tool.ts b/src/agents/tools/image-generate-tool.ts
index ceae69bfc15..a2f04e2086a 100644
--- a/src/agents/tools/image-generate-tool.ts
+++ b/src/agents/tools/image-generate-tool.ts
@@ -16,6 +16,7 @@ import { getImageMetadata } from "../../media/image-ops.js";
 import { saveMediaBuffer } from "../../media/store.js";
 import { loadWebMedia } from "../../media/web-media.js";
 import { getProviderEnvVars } from "../../secrets/provider-env-vars.js";
+import { normalizeOptionalLowercaseString } from "../../shared/string-coerce.js";
 import { resolveUserPath } from "../../utils.js";
 import { normalizeProviderId } from "../provider-id.js";
 import { ToolInputError, readNumberParam, readStringParam } from "./common.js";
@@ -213,7 +214,7 @@ function resolveAction(args: Record<string, unknown>): "generate" | "list" {
   if (!raw) {
     return "generate";
   }
-  const normalized = raw.trim().toLowerCase();
+  const normalized = normalizeOptionalLowercaseString(raw);
   if (normalized === "generate" || normalized === "list") {
     return normalized;
   }
diff --git a/src/agents/tools/music-generate-tool.ts b/src/agents/tools/music-generate-tool.ts
index edd66ab2207..ed68f44e034 100644
--- a/src/agents/tools/music-generate-tool.ts
+++ b/src/agents/tools/music-generate-tool.ts
@@ -17,6 +17,7 @@ import type {
   MusicGenerationSourceImage,
 } from "../../music-generation/types.js";
 import { readSnakeCaseParamRaw } from "../../param-key.js";
+import { normalizeOptionalLowercaseString } from "../../shared/string-coerce.js";
 import { resolveUserPath } from "../../utils.js";
 import type { DeliveryContext } from "../../utils/delivery-context.js";
 import {
@@ -144,7 +145,7 @@ function resolveAction(args: Record<string, unknown>): "generate" | "list" | "st
   if (!raw) {
     return "generate";
   }
-  const normalized = raw.trim().toLowerCase();
+  const normalized = normalizeOptionalLowercaseString(raw);
   if (normalized === "generate" || normalized === "list" || normalized === "status") {
     return normalized;
   }
@@ -157,7 +158,7 @@ function readBooleanParam(params: Record<string, unknown>, key: string): boolean
     return raw;
   }
   if (typeof raw === "string") {
-    const normalized = raw.trim().toLowerCase();
+    const normalized = normalizeOptionalLowercaseString(raw);
     if (normalized === "true") {
       return true;
     }
@@ -169,7 +170,9 @@ function readBooleanParam(params: Record<string, unknown>, key: string): boolean
 }
 
 function normalizeOutputFormat(raw: string | undefined): MusicGenerationOutputFormat | undefined {
-  const normalized = raw?.trim().toLowerCase() as MusicGenerationOutputFormat | undefined;
+  const normalized = normalizeOptionalLowercaseString(raw) as
+    | MusicGenerationOutputFormat
+    | undefined;
   if (!normalized) {
     return undefined;
   }
diff --git a/src/agents/tools/nodes-tool-commands.ts b/src/agents/tools/nodes-tool-commands.ts
index cede378579d..fc604713849 100644
--- a/src/agents/tools/nodes-tool-commands.ts
+++ b/src/agents/tools/nodes-tool-commands.ts
@@ -1,6 +1,7 @@
 import crypto from "node:crypto";
 import { parseTimeoutMs } from "../../cli/parse-timeout.js";
 import { formatErrorMessage } from "../../infra/errors.js";
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
 import { jsonResult, readStringParam } from "./common.js";
 import type { GatewayCallOptions } from "./gateway.js";
 import { callGatewayTool } from "./gateway.js";
@@ -53,10 +54,7 @@ export async function executeNodeCommandAction(params: {
     case "notifications_action": {
       const node = readStringParam(params.input, "node", { required: true });
       const notificationKey = readStringParam(params.input, "notificationKey", { required: true });
-      const notificationAction =
-        typeof params.input.notificationAction === "string"
-          ? params.input.notificationAction.trim().toLowerCase()
-          : "";
+      const notificationAction = normalizeLowercaseStringOrEmpty(params.input.notificationAction);
       if (
         notificationAction !== "open" &&
         notificationAction !== "dismiss" &&
@@ -118,7 +116,7 @@ export async function executeNodeCommandAction(params: {
       const node = readStringParam(params.input, "node", { required: true });
       const nodeId = await resolveNodeId(params.gatewayOpts, node);
       const invokeCommand = readStringParam(params.input, "invokeCommand", { required: true });
-      const invokeCommandNormalized = invokeCommand.trim().toLowerCase();
+      const invokeCommandNormalized = normalizeLowercaseStringOrEmpty(invokeCommand);
       if (BLOCKED_INVOKE_COMMANDS.has(invokeCommandNormalized)) {
         throw new Error(
           `invokeCommand "${invokeCommand}" is reserved for shell execution; use exec with host=node instead`,
diff --git a/src/agents/tools/sessions-list-tool.ts b/src/agents/tools/sessions-list-tool.ts
index 79407983294..4c99f51d136 100644
--- a/src/agents/tools/sessions-list-tool.ts
+++ b/src/agents/tools/sessions-list-tool.ts
@@ -8,7 +8,7 @@ import {
 } from "../../config/sessions.js";
 import { callGateway } from "../../gateway/call.js";
 import { resolveAgentIdFromSessionKey } from "../../routing/session-key.js";
-import { readStringValue } from "../../shared/string-coerce.js";
+import { normalizeOptionalLowercaseString, readStringValue } from "../../shared/string-coerce.js";
 import {
   describeSessionsListTool,
   SESSIONS_LIST_TOOL_DISPLAY_SUMMARY,
@@ -75,9 +75,9 @@ export function createSessionsListTool(opts?: {
         sandboxed: opts?.sandboxed === true,
       });
 
-      const kindsRaw = readStringArrayParam(params, "kinds")?.map((value) =>
-        value.trim().toLowerCase(),
-      );
+      const kindsRaw = readStringArrayParam(params, "kinds")
+        ?.map((value) => normalizeOptionalLowercaseString(value))
+        .filter(Boolean);
       const allowedKindsList = (kindsRaw ?? []).filter((value) =>
         ["main", "group", "cron", "hook", "node", "other"].includes(value),
       );
diff --git a/src/agents/tools/video-generate-tool.ts b/src/agents/tools/video-generate-tool.ts
index 73eb7b48892..7eb211711c5 100644
--- a/src/agents/tools/video-generate-tool.ts
+++ b/src/agents/tools/video-generate-tool.ts
@@ -6,6 +6,7 @@ import { createSubsystemLogger } from "../../logging/subsystem.js";
 import { saveMediaBuffer } from "../../media/store.js";
 import { loadWebMedia } from "../../media/web-media.js";
 import { readSnakeCaseParamRaw } from "../../param-key.js";
+import { normalizeOptionalLowercaseString } from "../../shared/string-coerce.js";
 import { resolveUserPath } from "../../utils.js";
 import type { DeliveryContext } from "../../utils/delivery-context.js";
 import {
@@ -163,7 +164,7 @@ function resolveAction(args: Record<string, unknown>): "generate" | "list" | "st
   if (!raw) {
     return "generate";
   }
-  const normalized = raw.trim().toLowerCase();
+  const normalized = normalizeOptionalLowercaseString(raw);
   if (normalized === "generate" || normalized === "list" || normalized === "status") {
     return normalized;
   }
@@ -205,7 +206,7 @@ function readBooleanParam(params: Record<string, unknown>, key: string): boolean
     return raw;
   }
   if (typeof raw === "string") {
-    const normalized = raw.trim().toLowerCase();
+    const normalized = normalizeOptionalLowercaseString(raw);
     if (normalized === "true") {
       return true;
     }
diff --git a/src/agents/tools/web-shared.ts b/src/agents/tools/web-shared.ts
index da0fbb38beb..d335df4a927 100644
--- a/src/agents/tools/web-shared.ts
+++ b/src/agents/tools/web-shared.ts
@@ -1,3 +1,5 @@
+import { normalizeLowercaseStringOrEmpty } from "../../shared/string-coerce.js";
+
 export type CacheEntry<T> = {
   value: T;
   expiresAt: number;
@@ -20,7 +22,7 @@ export function resolveCacheTtlMs(value: unknown, fallbackMinutes: number): numb
 }
 
 export function normalizeCacheKey(value: string): string {
-  return value.trim().toLowerCase();
+  return normalizeLowercaseStringOrEmpty(value);
 }
 
 export function readCache<T>(