cmd/mavend/actions_act.go

@@ -53,6 +53,13 @@ func (h *reactiveHandler) actionAct(ctx context.Context, dec router.Decision) st
 			return "выполнить «" + phrase + "»? скажи «да» или «нет»."
 		case errors.Is(err, tool.ErrNotEnabled):
 			return h.proposeGap(ctx, dec)
+		case errors.Is(err, tool.ErrNotConnected), errors.Is(err, mcp.ErrNotConnected), errors.Is(err, mcp.ErrNoServer):
+			// The row is enabled and the backend is gone. Drafting a proposal
+			// for it (the ErrNotEnabled path) would be answering the wrong
+			// question.
+			return "этот инструмент включён, но сервер, который его выполняет, сейчас не подключён."
+		case errors.Is(err, mcp.ErrToolGone):
+			return "сервер больше не предлагает этот инструмент — я сняла его с разрешённых, посмотри на /tools."
 		case errors.Is(err, mcp.ErrNeedsArgs):
 			// An MCP tool that wants named arguments a spoken verb cannot
 			// supply. Guessing them would be a wrong act, so she says so

internal/tool/tool.go

@@ -60,6 +60,13 @@ var (
 	ErrNotEnabled = errors.New("tool not on the enabled allowlist")
 	// ErrNeedsConfirm — the fn is enabled but destructive; needs a confirm turn.
 	ErrNeedsConfirm = errors.New("destructive tool needs confirmation")
+	// ErrNotConnected — the row is enabled and well formed, but the thing it
+	// dispatches to is not wired: the mcp block was dropped from the config
+	// while enabled MCP rows remained, or the same for the house. Held apart
+	// from ErrNotEnabled because the act path turns that one into a fresh
+	// proposal, and drafting a new proposal for a tool that already exists and
+	// is enabled is a lie about what is wrong.
+	ErrNotConnected = errors.New("tool is enabled but its backend is not connected")
 )
 
 // MCPCaller is the seam for an act that is an MCP tool call rather than a
@@ -134,7 +141,7 @@ func (e *Executor) Exec(ctx context.Context, name string, args []string, confirm
 	// confirmed. Only the dispatch differs.
 	if server, remote, ok := mcp.ParseCmd(t.Cmd); ok {
 		if e.mcp == nil {
-			return "", ErrNotEnabled
+			return "", fmt.Errorf("%w: %s is an MCP tool and no mcp block is configured", ErrNotConnected, name)
 		}
 		ctx, cancel := context.WithTimeout(ctx, e.timeout)
 		defer cancel()
@@ -148,7 +155,7 @@ func (e *Executor) Exec(ctx context.Context, name string, args []string, confirm
 	// row but can never compose a target of its own.
 	if entityID, service, ok := smarthome.ParseCmd(t.Cmd); ok {
 		if e.home == nil {
-			return "", ErrNotEnabled
+			return "", fmt.Errorf("%w: %s is a house tool and no smarthome block is configured", ErrNotConnected, name)
 		}
 		ctx, cancel := context.WithTimeout(ctx, e.timeout)
 		defer cancel()

internal/tool/tool_test.go

@@ -178,8 +178,15 @@ func TestExecMCPRowWithoutCallerRefuses(t *testing.T) {
 	ran := false
 	e := NewExecutor(api, time.Second)
 	e.run = func(context.Context, []string) (string, error) { ran = true; return "", nil }
-	if _, err := e.Exec(context.Background(), "vikunja_list_tasks", nil, false); !errors.Is(err, ErrNotEnabled) {
-		t.Fatalf("err = %v, want ErrNotEnabled", err)
+	err := func() error { _, e2 := e.Exec(context.Background(), "vikunja_list_tasks", nil, false); return e2 }()
+	// ErrNotConnected, NOT ErrNotEnabled: the act path turns ErrNotEnabled into
+	// a fresh proposal, and drafting a proposal for a row that already exists
+	// and is enabled answers the wrong question.
+	if !errors.Is(err, ErrNotConnected) {
+		t.Fatalf("err = %v, want ErrNotConnected", err)
+	}
+	if errors.Is(err, ErrNotEnabled) {
+		t.Fatal("an enabled row with a missing backend must not read as not-enabled")
 	}
 	if ran {
 		t.Fatal(`"mcp" must never be run as a binary`)
@@ -222,8 +229,8 @@ func TestExecSmartHomeRow(t *testing.T) {
 	}
 
 	// No house configured ⇒ the row refuses rather than being exec'd.
-	if _, err := newExec(nil).Exec(context.Background(), "home_light_x_off", nil, true); !errors.Is(err, ErrNotEnabled) {
-		t.Fatalf("unconfigured house: err = %v, want ErrNotEnabled", err)
+	if _, err := newExec(nil).Exec(context.Background(), "home_light_x_off", nil, true); !errors.Is(err, ErrNotConnected) {
+		t.Fatalf("unconfigured house: err = %v, want ErrNotConnected", err)
 	}
 	if ran {
 		t.Fatal(`"smarthome" was run as a binary`)