diff --git a/app/src/components/settings/panels/ToolPolicyDiagnosticsPanel.test.tsx b/app/src/components/settings/panels/ToolPolicyDiagnosticsPanel.test.tsx
new file mode 100644
index 000000000..b8b9dcf23
--- /dev/null
+++ b/app/src/components/settings/panels/ToolPolicyDiagnosticsPanel.test.tsx
@@ -0,0 +1,77 @@
+import { render, screen, waitFor } from '@testing-library/react';
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+
+import ToolPolicyDiagnosticsPanel from './ToolPolicyDiagnosticsPanel';
+
+const navigateBack = vi.fn();
+
+vi.mock('../hooks/useSettingsNavigation', () => ({
+  useSettingsNavigation: () => ({
+    navigateBack,
+    breadcrumbs: [{ label: 'Settings' }, { label: 'Tool Policy' }],
+  }),
+}));
+
+vi.mock('../components/SettingsBackButton', () => ({
+  default: ({ onBack }: { onBack?: () => void }) => (
+    <button type="button" data-testid="settings-header-back" onClick={onBack}>
+      back
+    </button>
+  ),
+}));
+
+const callCoreRpc = vi.fn();
+vi.mock('../../../services/coreRpcClient', () => ({
+  callCoreRpc: (arg: { method: string; params: unknown }) => callCoreRpc(arg),
+}));
+
+function diagnosticsResult(autonomyLevel = 'supervised') {
+  return {
+    total_tools: 12,
+    enabled_tools: 9,
+    mcp_stdio_tools: 3,
+    json_rpc_tools: 9,
+    possible_write_surfaces: ['memory.put'],
+    policy_surfaces: ['tool_registry.diagnostics'],
+    posture: {
+      autonomy_level: autonomyLevel,
+      workspace_only: true,
+      max_actions_per_hour: 30,
+      require_approval_for_medium_risk: true,
+      block_high_risk_commands: true,
+    },
+    mcp_allowlists: { enabled: false, server_count: 0, enabled_server_count: 0, servers: [] },
+    mcp_write_audit: { enabled: false, recent_rows: null, last_error: null },
+    recent_denials: [],
+  };
+}
+
+beforeEach(() => {
+  vi.clearAllMocks();
+  callCoreRpc.mockResolvedValue(diagnosticsResult());
+});
+
+describe('<ToolPolicyDiagnosticsPanel />', () => {
+  // Regression for TAURI-RUST-83E: the panel previously called the bare,
+  // unregistered `tool_registry.diagnostics`, which the core dispatcher rejects
+  // with "unknown method" (the registered name is the namespaced
+  // `openhuman.tool_registry_diagnostics`). The mismatch broke the panel for
+  // every user and flooded Sentry. Pin the exact registered method name.
+  it('invokes the registered openhuman.tool_registry_diagnostics RPC method', async () => {
+    render(<ToolPolicyDiagnosticsPanel />);
+
+    await waitFor(() => {
+      expect(callCoreRpc).toHaveBeenCalledWith(
+        expect.objectContaining({ method: 'openhuman.tool_registry_diagnostics' })
+      );
+    });
+  });
+
+  it('renders the diagnostics posture once the RPC resolves', async () => {
+    render(<ToolPolicyDiagnosticsPanel />);
+
+    // The autonomy level only renders in the ready state, so finding it also
+    // proves the panel left loading and did not fall into the error branch.
+    expect(await screen.findByText('supervised')).toBeInTheDocument();
+  });
+});