diff --git a/extensions/voice-call/src/core-bridge.ts b/extensions/voice-call/src/core-bridge.ts
index 8c3981db3467..c1c0bc244c48 100644
--- a/extensions/voice-call/src/core-bridge.ts
+++ b/extensions/voice-call/src/core-bridge.ts
@@ -1,6 +1,9 @@
 import type { OpenClawPluginApi } from "../api.js";
 import type { VoiceCallTtsConfig } from "./config.js";
 
+// Narrow core runtime/config contracts consumed by the voice-call plugin.
+
+/** Core config subset read by voice-call helpers. */
 export type CoreConfig = {
   session?: {
     store?: string;
@@ -11,4 +14,5 @@ export type CoreConfig = {
   [key: string]: unknown;
 };
 
+/** Agent runtime API subset exposed through the plugin SDK. */
 export type CoreAgentDeps = OpenClawPluginApi["runtime"]["agent"];
diff --git a/extensions/voice-call/src/deep-merge.ts b/extensions/voice-call/src/deep-merge.ts
index b79ade926aba..f6a76bb301d7 100644
--- a/extensions/voice-call/src/deep-merge.ts
+++ b/extensions/voice-call/src/deep-merge.ts
@@ -1,7 +1,10 @@
 import { isRecord as isPlainObject } from "openclaw/plugin-sdk/string-coerce-runtime";
 
+// Prototype-safe deep merge for config overrides that ignores undefined values.
+
 const BLOCKED_MERGE_KEYS = new Set(["__proto__", "prototype", "constructor"]);
 
+/** Deep-merge plain objects, keeping base values when overrides are undefined. */
 export function deepMergeDefined(base: unknown, override: unknown): unknown {
   if (!isPlainObject(base) || !isPlainObject(override)) {
     return override === undefined ? base : override;
@@ -13,6 +16,7 @@ export function deepMergeDefined(base: unknown, override: unknown): unknown {
       continue;
     }
 
+    // Blocked keys above prevent prototype pollution while preserving normal nested overrides.
     const existing = result[key];
     result[key] = key in result ? deepMergeDefined(existing, value) : value;
   }
diff --git a/extensions/voice-call/src/http-headers.ts b/extensions/voice-call/src/http-headers.ts
index 3a3785dd9fe0..d3fdafbc229e 100644
--- a/extensions/voice-call/src/http-headers.ts
+++ b/extensions/voice-call/src/http-headers.ts
@@ -1,7 +1,10 @@
 import { normalizeLowercaseStringOrEmpty } from "openclaw/plugin-sdk/string-coerce-runtime";
 
+// Case-insensitive HTTP header lookup for provider webhook handlers.
+
 type HttpHeaderMap = Record<string, string | string[] | undefined>;
 
+/** Return the first value for a header name regardless of caller casing. */
 export function getHeader(headers: HttpHeaderMap, name: string): string | undefined {
   const target = normalizeLowercaseStringOrEmpty(name);
   const direct = headers[target];
diff --git a/extensions/voice-call/src/realtime-agent-context.ts b/extensions/voice-call/src/realtime-agent-context.ts
index 8406a281d1e0..692e9abdeb91 100644
--- a/extensions/voice-call/src/realtime-agent-context.ts
+++ b/extensions/voice-call/src/realtime-agent-context.ts
@@ -5,6 +5,9 @@ import { normalizeOptionalString as normalizeString } from "openclaw/plugin-sdk/
 import type { VoiceCallConfig } from "./config.js";
 import type { CoreAgentDeps, CoreConfig } from "./core-bridge.js";
 
+// Builds compact agent context injected into realtime voice sessions.
+
+/** Agent identity subset used by voice instructions. */
 type VoiceIdentityLike = {
   name?: unknown;
   emoji?: unknown;
@@ -13,6 +16,7 @@ type VoiceIdentityLike = {
   vibe?: unknown;
 };
 
+/** Limit injected context while preserving an explicit truncation marker. */
 function limitText(text: string, maxChars: number): string {
   if (text.length <= maxChars) {
     return text;
@@ -20,6 +24,7 @@ function limitText(text: string, maxChars: number): string {
   return `${text.slice(0, Math.max(0, maxChars - 32)).trimEnd()}\n[truncated]`;
 }
 
+/** Read configured workspace context files through the safe workspace root. */
 async function readWorkspaceVoiceContextFiles(params: {
   workspaceDir: string;
   files: readonly string[];
@@ -48,6 +53,7 @@ async function readWorkspaceVoiceContextFiles(params: {
   return sections;
 }
 
+/** Build final realtime instructions from base instructions, consult policy, and fast context. */
 export async function buildRealtimeVoiceInstructions(params: {
   baseInstructions: string;
   config: VoiceCallConfig;
@@ -98,6 +104,7 @@ export async function buildRealtimeVoiceInstructions(params: {
       params.coreConfig as OpenClawConfig,
       agentId,
     );
+    // Workspace reads stay under the agent root; missing or unreadable context files are omitted.
     const fileSections = await readWorkspaceVoiceContextFiles({
       workspaceDir,
       files: contextConfig.files,
diff --git a/extensions/voice-call/src/realtime-defaults.ts b/extensions/voice-call/src/realtime-defaults.ts
index b6c6adb981cb..01a5bda15020 100644
--- a/extensions/voice-call/src/realtime-defaults.ts
+++ b/extensions/voice-call/src/realtime-defaults.ts
@@ -1,3 +1,6 @@
 import { REALTIME_VOICE_AGENT_CONSULT_TOOL_NAME } from "openclaw/plugin-sdk/realtime-voice";
 
+// Default realtime instructions for the voice-call plugin's phone interface.
+
+/** Baseline instructions that keep realtime calls brief and route deep work to agent consult. */
 export const DEFAULT_VOICE_CALL_REALTIME_INSTRUCTIONS = `You are OpenClaw's phone-call realtime voice interface. Keep spoken replies brief and natural. When a question needs deeper reasoning, current information, or tools, call ${REALTIME_VOICE_AGENT_CONSULT_TOOL_NAME} before answering.`;
diff --git a/extensions/voice-call/src/realtime-fast-context.ts b/extensions/voice-call/src/realtime-fast-context.ts
index 0065b5f15208..14bc0bc33d31 100644
--- a/extensions/voice-call/src/realtime-fast-context.ts
+++ b/extensions/voice-call/src/realtime-fast-context.ts
@@ -9,6 +9,9 @@ type Logger = {
   debug?: (message: string) => void;
 };
 
+// Voice-call labels for the SDK realtime fast-context resolver.
+
+/** Resolve fast-context consult data using caller-oriented labels. */
 export async function resolveRealtimeFastContextConsult(params: {
   cfg: OpenClawConfig;
   agentId: string;
diff --git a/extensions/voice-call/src/response-model.ts b/extensions/voice-call/src/response-model.ts
index 805afa892c21..28fdd5d39729 100644
--- a/extensions/voice-call/src/response-model.ts
+++ b/extensions/voice-call/src/response-model.ts
@@ -1,6 +1,9 @@
 import type { VoiceCallConfig } from "./config.js";
 import type { CoreAgentDeps } from "./core-bridge.js";
 
+// Resolves the model used for voice-call text response generation.
+
+/** Resolve provider/model fields from explicit voice config or agent defaults. */
 export function resolveVoiceResponseModel(params: {
   voiceConfig: VoiceCallConfig;
   agentRuntime: CoreAgentDeps;
diff --git a/extensions/voice-call/src/telephony-tts.ts b/extensions/voice-call/src/telephony-tts.ts
index 6302914429df..7ec2d00f976f 100644
--- a/extensions/voice-call/src/telephony-tts.ts
+++ b/extensions/voice-call/src/telephony-tts.ts
@@ -10,6 +10,9 @@ import type { CoreConfig } from "./core-bridge.js";
 import { deepMergeDefined } from "./deep-merge.js";
 import { convertPcmToMulaw8k } from "./telephony-audio.js";
 
+// Telephony TTS adapter that applies voice-call overrides and emits 8kHz mulaw audio.
+
+/** Core runtime TTS API used by the telephony adapter. */
 export type TelephonyTtsRuntime = {
   textToSpeechTelephony: (params: {
     text: string;
@@ -27,13 +30,16 @@ export type TelephonyTtsRuntime = {
   }>;
 };
 
+/** Provider facade used by Twilio/webhook code for telephony synthesis. */
 export type TelephonyTtsProvider = {
   synthesisTimeoutMs: number;
   synthesizeForTelephony: (text: string) => Promise<Buffer>;
 };
 
+/** Default timeout for one telephony synthesis request. */
 export const TELEPHONY_DEFAULT_TTS_TIMEOUT_MS = 8000;
 
+/** Voice-call override policy for inline TTS model directives. */
 type TelephonyModelOverrideConfig = {
   enabled?: boolean;
   allowText?: boolean;
@@ -45,6 +51,7 @@ type TelephonyModelOverrideConfig = {
   allowSeed?: boolean;
 };
 
+/** Create a TTS provider that honors voice-call overrides and converts PCM to mulaw. */
 export function createTelephonyTtsProvider(params: {
   coreConfig: CoreConfig;
   ttsOverride?: VoiceCallTtsConfig;
@@ -107,6 +114,7 @@ export function createTelephonyTtsProvider(params: {
   };
 }
 
+/** Apply voice-call TTS overrides to core config without mutating the original object. */
 function applyTtsOverride(coreConfig: CoreConfig, override?: VoiceCallTtsConfig): CoreConfig {
   if (!override) {
     return coreConfig;
@@ -127,6 +135,7 @@ function applyTtsOverride(coreConfig: CoreConfig, override?: VoiceCallTtsConfig)
   };
 }
 
+/** Merge core and voice-call TTS config, keeping undefined override fields out. */
 function mergeTtsConfig(
   base?: VoiceCallTtsConfig,
   override?: VoiceCallTtsConfig,
@@ -143,6 +152,7 @@ function mergeTtsConfig(
   return deepMergeDefined(base, override) as VoiceCallTtsConfig;
 }
 
+/** Resolve directive override policy for telephony synthesis. */
 function resolveTelephonyModelOverridePolicy(
   overrides: TelephonyModelOverrideConfig | undefined,
 ): SpeechModelOverridePolicy {
@@ -172,6 +182,7 @@ function resolveTelephonyModelOverridePolicy(
   };
 }
 
+/** Read model override policy from TTS config when present. */
 function readTelephonyModelOverrides(
   ttsConfig: VoiceCallTtsConfig | undefined,
 ): TelephonyModelOverrideConfig | undefined {
@@ -181,16 +192,19 @@ function readTelephonyModelOverrides(
     : undefined;
 }
 
+/** Normalize provider ids for config lookup. */
 function normalizeProviderId(value: unknown): string | undefined {
   return typeof value === "string" ? value.trim().toLowerCase() || undefined : undefined;
 }
 
+/** Coerce provider config objects while rejecting arrays and primitives. */
 function asProviderConfig(value: unknown): SpeechProviderConfig {
   return value && typeof value === "object" && !Array.isArray(value)
     ? (value as SpeechProviderConfig)
     : {};
 }
 
+/** Collect named provider configs from canonical and legacy TTS config shapes. */
 function collectTelephonyProviderConfigs(
   ttsConfig: VoiceCallTtsConfig | undefined,
 ): Record<string, SpeechProviderConfig> {
diff --git a/extensions/voice-call/src/webhook.types.ts b/extensions/voice-call/src/webhook.types.ts
index 8bc758154dce..3491508ba6c9 100644
--- a/extensions/voice-call/src/webhook.types.ts
+++ b/extensions/voice-call/src/webhook.types.ts
@@ -1,3 +1,6 @@
+// Shared webhook response contract for voice-call providers.
+
+/** HTTP response payload returned by provider webhook handlers. */
 export type WebhookResponsePayload = {
   statusCode: number;
   body: string;