fix(mcp): expose channel payloads in primary content

CHANGELOG.md

@@ -48,6 +48,7 @@ Docs: https://docs.openclaw.ai
 - Control UI: point the Appearance tweakcn browse action and docs at the live tweakcn editor route instead of the removed `/themes` page. Fixes #77048.
 - Control UI: render Dream Diary prose through the sanitized markdown pipeline, so diary bold/italic/header markdown no longer appears as literal source text. Fixes #62413.
 - Control UI: render tool results whose output arrives as text-block arrays and give expanded tool output a scrollable block, so read/exec output remains visible in WebChat. Fixes #77054.
+- MCP: include serialized conversation/message payloads in the primary text content for `conversations_list` and `messages_read`, while preserving `structuredContent` for capable clients. Fixes #77024.
 - Diagnostics: keep webhook/message OTEL attributes and Prometheus delivery labels low-cardinality and omit raw chat/message IDs from spans, so progress-draft and message-tool modes do not leak high-cardinality messaging identifiers.
 - Google Meet: stop advertising legacy `mode: "realtime"` to agents and config UIs, while keeping it as a hidden compatibility alias for `mode: "agent"`, so new joins use the STT -> OpenClaw agent -> TTS path instead of selecting the direct realtime voice fallback.
 - Google Meet: add `chrome.audioBufferBytes` for generated command-pair SoX audio commands and lower the default buffer from SoX's 8192 bytes to 4096 bytes to reduce Chrome talk-back latency.

src/mcp/channel-server.test.ts

@@ -176,6 +176,55 @@ describe("openclaw channel mcp server", () => {
         );
       });
 
+      test("serializes conversation and message payloads into MCP primary content", async () => {
+        const mcp = await connectMcpWithoutGateway({ claudeChannelMode: "off" });
+        try {
+          const gatewayRequest = vi.fn(async (method: string) => {
+            if (method === "sessions.list") {
+              return {
+                sessions: [
+                  {
+                    key: "agent:main:telegram:direct:123",
+                    channel: "telegram",
+                    deliveryContext: { to: "123" },
+                    lastMessagePreview: "hello",
+                  },
+                ],
+              };
+            }
+            if (method === "sessions.get") {
+              return {
+                messages: [
+                  {
+                    id: "msg-1",
+                    role: "assistant",
+                    content: [{ type: "text", text: "full transcript text" }],
+                  },
+                ],
+              };
+            }
+            throw new Error(`unexpected gateway method ${method}`);
+          });
+          attachReadyGateway(mcp.bridge, gatewayRequest);
+
+          const conversations = (await mcp.client.callTool({
+            name: "conversations_list",
+            arguments: {},
+          })) as { content?: Array<{ type: string; text?: string }> };
+          expect(conversations.content?.[0]?.text).toContain('"sessionKey"');
+          expect(conversations.content?.[0]?.text).toContain('"lastMessagePreview": "hello"');
+
+          const messages = (await mcp.client.callTool({
+            name: "messages_read",
+            arguments: { session_key: "agent:main:telegram:direct:123" },
+          })) as { content?: Array<{ type: string; text?: string }> };
+          expect(messages.content?.[0]?.text).toContain('"id": "msg-1"');
+          expect(messages.content?.[0]?.text).toContain("full transcript text");
+        } finally {
+          await mcp.close();
+        }
+      });
+
       test("emits Claude channel and permission notifications", async () => {
         const sessionKey = "agent:main:main";
         let mcp: Awaited<ReturnType<typeof connectMcpWithoutGateway>> | null = null;

src/mcp/channel-shared.ts

@@ -149,6 +149,16 @@ export function summarizeResult(
   };
 }
 
+export function summarizeStructuredResult(
+  label: string,
+  count: number,
+  payload: unknown,
+): { content: Array<{ type: "text"; text: string }> } {
+  return {
+    content: [{ type: "text", text: `${label}: ${count}\n\n${JSON.stringify(payload, null, 2)}` }],
+  };
+}
+
 function resolveConversationChannel(row: SessionRow): string | undefined {
   return normalizeMessageChannel(
     toText(row.deliveryContext?.channel) ??

src/mcp/channel-tools.ts

@@ -5,6 +5,7 @@ import {
   extractAttachmentsFromMessage,
   resolveMessageId,
   summarizeResult,
+  summarizeStructuredResult,
   toText,
 } from "./channel-shared.js";
 
@@ -34,7 +35,7 @@ export function registerChannelMcpTools(server: McpServer, bridge: OpenClawChann
     async (args) => {
       const conversations = await bridge.listConversations(args);
       return {
-        ...summarizeResult("conversations", conversations.length),
+        ...summarizeStructuredResult("conversations", conversations.length, { conversations }),
         structuredContent: { conversations },
       };
     },
@@ -69,7 +70,7 @@ export function registerChannelMcpTools(server: McpServer, bridge: OpenClawChann
     async ({ session_key, limit }) => {
       const messages = await bridge.readMessages(session_key, limit ?? 20);
       return {
-        ...summarizeResult("messages", messages.length),
+        ...summarizeStructuredResult("messages", messages.length, { messages }),
         structuredContent: { messages },
       };
     },