diff --git a/apps/client/src/features/workspace/components/settings/components/ai-mcp-server-test-view.test.ts b/apps/client/src/features/workspace/components/settings/components/ai-mcp-server-test-view.test.ts
index cde45cc6..60b10c4e 100644
--- a/apps/client/src/features/workspace/components/settings/components/ai-mcp-server-test-view.test.ts
+++ b/apps/client/src/features/workspace/components/settings/components/ai-mcp-server-test-view.test.ts
@@ -56,4 +56,32 @@ describe("mcpTestButtonView", () => {
       tooltip: "402: nope",
     });
   });
+
+  it("failed when the request itself rejects (no result payload)", () => {
+    // 401/403/500/network: there is no { ok } body, only a thrown error. The
+    // row must still show a red "Failed" rather than reverting to idle "Test".
+    expect(
+      mcpTestButtonView(undefined, t, {
+        response: { data: { message: "Unauthorized" } },
+      }),
+    ).toEqual({
+      state: "failed",
+      color: "red",
+      variant: "light",
+      label: "Failed",
+      tooltip: "Unauthorized",
+    });
+  });
+
+  it("reject without a server message falls back to the generic label", () => {
+    // A bare network error (no response body) still surfaces as failed, using
+    // the i18n fallback for the tooltip.
+    expect(mcpTestButtonView(undefined, t, new Error("network down"))).toEqual({
+      state: "failed",
+      color: "red",
+      variant: "light",
+      label: "Failed",
+      tooltip: "Failed to update data",
+    });
+  });
 });
diff --git a/apps/client/src/features/workspace/components/settings/components/ai-mcp-server-test-view.ts b/apps/client/src/features/workspace/components/settings/components/ai-mcp-server-test-view.ts
index b438935a..8f8db84c 100644
--- a/apps/client/src/features/workspace/components/settings/components/ai-mcp-server-test-view.ts
+++ b/apps/client/src/features/workspace/components/settings/components/ai-mcp-server-test-view.ts
@@ -3,6 +3,23 @@ import type { IAiMcpServerTestResult } from "@/features/workspace/services/ai-mc
 /** Minimal translator shape (i18next `t`): key + optional interpolation. */
 type Translate = (key: string, options?: Record<string, unknown>) => string;
 
+/** Subset of an axios-style rejection we read for the reject tooltip. */
+type McpTestRequestError = {
+  response?: { data?: { message?: string } };
+};
+
+/**
+ * Best-effort extraction of a server-sent message from a rejected test request
+ * (axios stores it at `error.response.data.message`). Returns undefined for a
+ * bare/network error so the caller can fall back to a generic label.
+ */
+function readRequestErrorMessage(error: unknown): string | undefined {
+  if (error && typeof error === "object" && "response" in error) {
+    return (error as McpTestRequestError).response?.data?.message;
+  }
+  return undefined;
+}
+
 /**
  * Presentation for the inline "Test" button, derived from the current test
  * result tristate (no result yet / ok / failed). Color is never the only signal
@@ -27,6 +44,7 @@ export interface McpTestButtonView {
 export function mcpTestButtonView(
   result: IAiMcpServerTestResult | undefined,
   t: Translate,
+  error?: unknown,
 ): McpTestButtonView {
   if (result?.ok) {
     return {
@@ -49,6 +67,19 @@ export function mcpTestButtonView(
       tooltip: result.error,
     };
   }
+  if (error) {
+    // The test request itself rejected (401/403/500/network) — there is no
+    // `{ ok }` payload, so without this branch the row would silently revert to
+    // the idle "Test" instead of reporting the failure. Tooltip prefers the
+    // server-sent message, else the generic i18n fallback.
+    return {
+      state: "failed",
+      color: "red",
+      variant: "light",
+      label: t("Failed"),
+      tooltip: readRequestErrorMessage(error) ?? t("Failed to update data"),
+    };
+  }
   return {
     state: "idle",
     color: undefined,
diff --git a/apps/client/src/features/workspace/components/settings/components/ai-mcp-servers.tsx b/apps/client/src/features/workspace/components/settings/components/ai-mcp-servers.tsx
index 5ccdb380..d0a19247 100644
--- a/apps/client/src/features/workspace/components/settings/components/ai-mcp-servers.tsx
+++ b/apps/client/src/features/workspace/components/settings/components/ai-mcp-servers.tsx
@@ -185,8 +185,15 @@ function AiMcpServerRow({
 
   // Single derivation of the button/tooltip presentation from the test tristate
   // (idle / ok / failed), so the two can never drift apart. Tooltip is "" while
-  // there is no result; the icon is mapped from `view.state` below.
-  const view = mcpTestButtonView(result, t);
+  // there is no result; the icon is mapped from `view.state` below. When the
+  // request itself rejects (401/403/500/network) there is no `data` payload, so
+  // we feed the mutation error in too — otherwise the row would silently revert
+  // to "Test" instead of showing a red "Failed".
+  const view = mcpTestButtonView(
+    result,
+    t,
+    testMutation.isError ? testMutation.error : undefined,
+  );
   const tooltipLabel = view.tooltip;
   const buttonColor = view.color;
   const buttonVariant = view.variant;
@@ -225,7 +232,7 @@ function AiMcpServerRow({
         {/* Always clickable: testing a disabled server before enabling it is useful. */}
         <Tooltip
           label={tooltipLabel}
-          disabled={!result}
+          disabled={view.state === "idle"}
           multiline
           maw={320}
           withinPortal