diff --git a/CHANGELOG.md b/CHANGELOG.md
index ddbfed2c2a1..821777455c6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -44,6 +44,7 @@ Docs: https://docs.openclaw.ai
 - Agents/Codex: flush accepted debounced steering messages before normal app-server turn cleanup, so inbound follow-ups acknowledged as queued are not dropped when the turn completes before the debounce fires. Thanks @vincentkoc.
 - Slack/interactive replies: keep rendered buttons and selects within Slack Block Kit value and count limits, and align command argument select values with Slack's option limit, so overlong agent-authored choices no longer make Slack reject the whole block payload. Thanks @slackapi.
 - Slack/interactive replies: drop overlong Block Kit button URLs while preserving valid callback values, so malformed link buttons no longer make Slack reject the whole interactive reply. Thanks @slackapi.
+- Slack/commands: truncate native command argument-menu confirmation text to Slack's dialog limit, so long plugin arg names no longer make fallback buttons render invalid Block Kit payloads. Thanks @slackapi.
 - Channels/WhatsApp: require Baileys outbound message ids before marking auto-replies delivered, so transcript text and ack reactions no longer make failed group replies look sent. Fixes #49225. Thanks @TinyTb.
 - CLI/update: scope packaged Node compile caches by OpenClaw version and install metadata, so global installs no longer reuse stale compiled chunks after package updates. Thanks @pashpashpash.
 - Channels/Voice call: keep pre-auth webhook in-flight limiting active when socket remote address metadata is missing, so slow-body requests from stripped-IP proxy paths still share the fallback bucket. (#74453) Thanks @davidangularme.
diff --git a/extensions/slack/src/monitor/slash.test.ts b/extensions/slack/src/monitor/slash.test.ts
index 8ebb9f9fe77..4c851bfe670 100644
--- a/extensions/slack/src/monitor/slash.test.ts
+++ b/extensions/slack/src/monitor/slash.test.ts
@@ -9,6 +9,7 @@ vi.mock("./slash-commands.runtime.js", () => {
   const reportLongCommand = { key: "reportlong", nativeName: "reportlong" };
   const reportLongButtonCommand = { key: "reportlongbutton", nativeName: "reportlongbutton" };
   const unsafeConfirmCommand = { key: "unsafeconfirm", nativeName: "unsafeconfirm" };
+  const longConfirmCommand = { key: "longconfirm", nativeName: "longconfirm" };
   const statusAliasCommand = { key: "status", nativeName: "status" };
   const periodArg = { name: "period", description: "period" };
   const baseReportPeriodChoices = [
@@ -78,6 +79,9 @@ vi.mock("./slash-commands.runtime.js", () => {
       if (normalized === "unsafeconfirm") {
         return unsafeConfirmCommand;
       }
+      if (normalized === "longconfirm") {
+        return longConfirmCommand;
+      }
       if (normalized === "agentstatus") {
         return statusAliasCommand;
       }
@@ -126,6 +130,12 @@ vi.mock("./slash-commands.runtime.js", () => {
         acceptsArgs: true,
         args: [],
       },
+      {
+        name: "longconfirm",
+        description: "LongConfirm",
+        acceptsArgs: true,
+        args: [],
+      },
       {
         name: "agentstatus",
         description: "Status",
@@ -179,6 +189,15 @@ vi.mock("./slash-commands.runtime.js", () => {
           ],
         };
       }
+      if (params.command?.key === "longconfirm") {
+        return {
+          arg: { name: `mode_${"x".repeat(320)}`, description: "mode" },
+          choices: [
+            { value: "on", label: "on" },
+            { value: "off", label: "off" },
+          ],
+        };
+      }
       if (params.command?.key !== "usage") {
         return null;
       }
@@ -428,6 +447,7 @@ describe("Slack native command argument menus", () => {
   let reportLongHandler: (args: unknown) => Promise<void>;
   let reportLongButtonHandler: (args: unknown) => Promise<void>;
   let unsafeConfirmHandler: (args: unknown) => Promise<void>;
+  let longConfirmHandler: (args: unknown) => Promise<void>;
   let agentStatusHandler: (args: unknown) => Promise<void>;
   let argMenuHandler: (args: unknown) => Promise<void>;
   let argMenuOptionsHandler: (args: unknown) => Promise<void>;
@@ -446,6 +466,7 @@ describe("Slack native command argument menus", () => {
       "/reportlongbutton",
     );
     unsafeConfirmHandler = requireHandler(harness.commands, "/unsafeconfirm", "/unsafeconfirm");
+    longConfirmHandler = requireHandler(harness.commands, "/longconfirm", "/longconfirm");
     agentStatusHandler = requireHandler(harness.commands, "/agentstatus", "/agentstatus");
     argMenuHandler = requireHandler(harness.actions, /^openclaw_cmdarg/, "arg-menu action");
     argMenuOptionsHandler = requireHandler(harness.options, "openclaw_cmdarg", "arg-menu options");
@@ -596,6 +617,16 @@ describe("Slack native command argument menus", () => {
     );
   });
 
+  it("truncates confirm dialog text when long args force button fallback", async () => {
+    const element = (await getFirstActionElementFromCommand(longConfirmHandler)) as
+      | { type?: string; confirm?: { text?: { text?: string } } }
+      | undefined;
+    const confirmText = element?.confirm?.text?.text;
+    expect(element?.type).toBe("button");
+    expect(confirmText).toHaveLength(300);
+    expect(confirmText?.endsWith("…")).toBe(true);
+  });
+
   it("dispatches the command when a menu button is clicked", async () => {
     await runArgMenuAction(argMenuHandler, {
       action: {
diff --git a/extensions/slack/src/monitor/slash.ts b/extensions/slack/src/monitor/slash.ts
index 8769da337f0..b551bd1f85a 100644
--- a/extensions/slack/src/monitor/slash.ts
+++ b/extensions/slack/src/monitor/slash.ts
@@ -55,6 +55,7 @@ const SLACK_COMMAND_ARG_SELECT_OPTIONS_MAX = 100;
 const SLACK_COMMAND_ARG_SELECT_OPTION_TEXT_MAX = 75;
 const SLACK_COMMAND_ARG_SELECT_OPTION_VALUE_MAX = 75;
 const SLACK_COMMAND_ARG_BUTTON_TEXT_MAX = 75;
+const SLACK_COMMAND_ARG_CONFIRM_TEXT_MAX = 300;
 const SLACK_HEADER_TEXT_MAX = 150;
 let slashCommandsRuntimePromise: Promise<typeof import("./slash-commands.runtime.js")> | null =
   null;
@@ -142,7 +143,10 @@ function buildSlackArgMenuConfirm(params: { command: string; arg: string }) {
     title: { type: "plain_text", text: "Confirm selection" },
     text: {
       type: "mrkdwn",
-      text: `Run */${command}* with *${arg}* set to this value?`,
+      text: truncateSlackText(
+        `Run */${command}* with *${arg}* set to this value?`,
+        SLACK_COMMAND_ARG_CONFIRM_TEXT_MAX,
+      ),
     },
     confirm: { type: "plain_text", text: "Run command" },
     deny: { type: "plain_text", text: "Cancel" },