diff --git a/src/agents/tools/message-tool.ts b/src/agents/tools/message-tool.ts
index 6552564e9..eae4356db 100644
--- a/src/agents/tools/message-tool.ts
+++ b/src/agents/tools/message-tool.ts
@@ -333,7 +333,13 @@ export function createMessageTool(options?: MessageToolOptions): AnyAgentTool {
     name: "message",
     description,
     parameters: schema,
-    execute: async (_toolCallId, args) => {
+    execute: async (_toolCallId, args, signal) => {
+      // Check if already aborted before doing any work
+      if (signal?.aborted) {
+        const err = new Error("Message send aborted");
+        err.name = "AbortError";
+        throw err;
+      }
       const params = args as Record<string, unknown>;
       const cfg = options?.config ?? loadConfig();
       const action = readStringParam(params, "action", {
@@ -366,6 +372,9 @@ export function createMessageTool(options?: MessageToolOptions): AnyAgentTool {
               currentThreadTs: options?.currentThreadTs,
               replyToMode: options?.replyToMode,
               hasRepliedRef: options?.hasRepliedRef,
+              // Direct tool invocations should not add cross-context decoration.
+              // The agent is composing a message, not forwarding from another chat.
+              skipCrossContextDecoration: true,
             }
           : undefined;
 
@@ -379,6 +388,7 @@ export function createMessageTool(options?: MessageToolOptions): AnyAgentTool {
         agentId: options?.agentSessionKey
           ? resolveSessionAgentId({ sessionKey: options.agentSessionKey, config: cfg })
           : undefined,
+        abortSignal: signal,
       });
 
       const toolResult = getToolResult(result);
diff --git a/src/channels/plugins/types.core.ts b/src/channels/plugins/types.core.ts
index 99f847fda..6a76743f2 100644
--- a/src/channels/plugins/types.core.ts
+++ b/src/channels/plugins/types.core.ts
@@ -240,6 +240,12 @@ export type ChannelThreadingToolContext = {
   currentThreadTs?: string;
   replyToMode?: "off" | "first" | "all";
   hasRepliedRef?: { value: boolean };
+  /**
+   * When true, skip cross-context decoration (e.g., "[from X]" prefix).
+   * Use this for direct tool invocations where the agent is composing a new message,
+   * not forwarding/relaying a message from another conversation.
+   */
+  skipCrossContextDecoration?: boolean;
 };
 
 export type ChannelMessagingAdapter = {
diff --git a/src/infra/outbound/message-action-runner.ts b/src/infra/outbound/message-action-runner.ts
index 50ddce227..2fe4cfeb6 100644
--- a/src/infra/outbound/message-action-runner.ts
+++ b/src/infra/outbound/message-action-runner.ts
@@ -64,6 +64,7 @@ export type RunMessageActionParams = {
   sessionKey?: string;
   agentId?: string;
   dryRun?: boolean;
+  abortSignal?: AbortSignal;
 };
 
 export type MessageActionRunResult =
@@ -507,6 +508,7 @@ type ResolvedActionContext = {
   input: RunMessageActionParams;
   agentId?: string;
   resolvedTarget?: ResolvedMessagingTarget;
+  abortSignal?: AbortSignal;
 };
 function resolveGateway(input: RunMessageActionParams): MessageActionRunnerGateway | undefined {
   if (!input.gateway) return undefined;
@@ -592,8 +594,28 @@ async function handleBroadcastAction(
   };
 }
 
+function throwIfAborted(abortSignal?: AbortSignal): void {
+  if (abortSignal?.aborted) {
+    const err = new Error("Message send aborted");
+    err.name = "AbortError";
+    throw err;
+  }
+}
+
 async function handleSendAction(ctx: ResolvedActionContext): Promise<MessageActionRunResult> {
-  const { cfg, params, channel, accountId, dryRun, gateway, input, agentId, resolvedTarget } = ctx;
+  const {
+    cfg,
+    params,
+    channel,
+    accountId,
+    dryRun,
+    gateway,
+    input,
+    agentId,
+    resolvedTarget,
+    abortSignal,
+  } = ctx;
+  throwIfAborted(abortSignal);
   const action: ChannelMessageActionName = "send";
   const to = readStringParam(params, "to", { required: true });
   // Support media, path, and filePath parameters for attachments
@@ -676,6 +698,7 @@ async function handleSendAction(ctx: ResolvedActionContext): Promise<MessageActi
   }
   const mirrorMediaUrls =
     mergedMediaUrls.length > 0 ? mergedMediaUrls : mediaUrl ? [mediaUrl] : undefined;
+  throwIfAborted(abortSignal);
   const send = await executeSendAction({
     ctx: {
       cfg,
@@ -695,6 +718,7 @@ async function handleSendAction(ctx: ResolvedActionContext): Promise<MessageActi
               mediaUrls: mirrorMediaUrls,
             }
           : undefined,
+      abortSignal,
     },
     to,
     message,
@@ -718,7 +742,8 @@ async function handleSendAction(ctx: ResolvedActionContext): Promise<MessageActi
 }
 
 async function handlePollAction(ctx: ResolvedActionContext): Promise<MessageActionRunResult> {
-  const { cfg, params, channel, accountId, dryRun, gateway, input } = ctx;
+  const { cfg, params, channel, accountId, dryRun, gateway, input, abortSignal } = ctx;
+  throwIfAborted(abortSignal);
   const action: ChannelMessageActionName = "poll";
   const to = readStringParam(params, "to", { required: true });
   const question = readStringParam(params, "pollQuestion", {
@@ -777,7 +802,8 @@ async function handlePollAction(ctx: ResolvedActionContext): Promise<MessageActi
 }
 
 async function handlePluginAction(ctx: ResolvedActionContext): Promise<MessageActionRunResult> {
-  const { cfg, params, channel, accountId, dryRun, gateway, input } = ctx;
+  const { cfg, params, channel, accountId, dryRun, gateway, input, abortSignal } = ctx;
+  throwIfAborted(abortSignal);
   const action = input.action as Exclude<ChannelMessageActionName, "send" | "poll" | "broadcast">;
   if (dryRun) {
     return {
@@ -930,6 +956,7 @@ export async function runMessageAction(
       input,
       agentId: resolvedAgentId,
       resolvedTarget,
+      abortSignal: input.abortSignal,
     });
   }
 
@@ -942,6 +969,7 @@ export async function runMessageAction(
       dryRun,
       gateway,
       input,
+      abortSignal: input.abortSignal,
     });
   }
 
@@ -953,5 +981,6 @@ export async function runMessageAction(
     dryRun,
     gateway,
     input,
+    abortSignal: input.abortSignal,
   });
 }
diff --git a/src/infra/outbound/message.ts b/src/infra/outbound/message.ts
index fcb90c295..6f5f88bd2 100644
--- a/src/infra/outbound/message.ts
+++ b/src/infra/outbound/message.ts
@@ -50,6 +50,7 @@ type MessageSendParams = {
     text?: string;
     mediaUrls?: string[];
   };
+  abortSignal?: AbortSignal;
 };
 
 export type MessageSendResult = {
@@ -167,6 +168,7 @@ export async function sendMessage(params: MessageSendParams): Promise<MessageSen
       gifPlayback: params.gifPlayback,
       deps: params.deps,
       bestEffort: params.bestEffort,
+      abortSignal: params.abortSignal,
       mirror: params.mirror
         ? {
             ...params.mirror,
diff --git a/src/infra/outbound/outbound-policy.ts b/src/infra/outbound/outbound-policy.ts
index 26a4d59e7..173e8314b 100644
--- a/src/infra/outbound/outbound-policy.ts
+++ b/src/infra/outbound/outbound-policy.ts
@@ -119,6 +119,8 @@ export async function buildCrossContextDecoration(params: {
   accountId?: string | null;
 }): Promise<CrossContextDecoration | null> {
   if (!params.toolContext?.currentChannelId) return null;
+  // Skip decoration for direct tool sends (agent composing, not forwarding)
+  if (params.toolContext.skipCrossContextDecoration) return null;
   if (!isCrossContextTarget(params)) return null;
 
   const markerConfig = params.cfg.tools?.message?.crossContext?.marker;
diff --git a/src/infra/outbound/outbound-send-service.ts b/src/infra/outbound/outbound-send-service.ts
index dd5dfd5e6..88a64d251 100644
--- a/src/infra/outbound/outbound-send-service.ts
+++ b/src/infra/outbound/outbound-send-service.ts
@@ -32,6 +32,7 @@ export type OutboundSendContext = {
     text?: string;
     mediaUrls?: string[];
   };
+  abortSignal?: AbortSignal;
 };
 
 function extractToolPayload(result: AgentToolResult<unknown>): unknown {
@@ -56,6 +57,14 @@ function extractToolPayload(result: AgentToolResult<unknown>): unknown {
   return result.content ?? result;
 }
 
+function throwIfAborted(abortSignal?: AbortSignal): void {
+  if (abortSignal?.aborted) {
+    const err = new Error("Message send aborted");
+    err.name = "AbortError";
+    throw err;
+  }
+}
+
 export async function executeSendAction(params: {
   ctx: OutboundSendContext;
   to: string;
@@ -70,6 +79,7 @@ export async function executeSendAction(params: {
   toolResult?: AgentToolResult<unknown>;
   sendResult?: MessageSendResult;
 }> {
+  throwIfAborted(params.ctx.abortSignal);
   if (!params.ctx.dryRun) {
     const handled = await dispatchChannelMessageAction({
       channel: params.ctx.channel,
@@ -103,6 +113,7 @@ export async function executeSendAction(params: {
     }
   }
 
+  throwIfAborted(params.ctx.abortSignal);
   const result: MessageSendResult = await sendMessage({
     cfg: params.ctx.cfg,
     to: params.to,
@@ -117,6 +128,7 @@ export async function executeSendAction(params: {
     deps: params.ctx.deps,
     gateway: params.ctx.gateway,
     mirror: params.ctx.mirror,
+    abortSignal: params.ctx.abortSignal,
   });
 
   return {