diff --git a/internal/ergo/plan_input.go b/internal/ergo/plan_input.go
index 4b18564..1334f40 100644
--- a/internal/ergo/plan_input.go
+++ b/internal/ergo/plan_input.go
@@ -14,11 +14,10 @@ import (
 	"strings"
 )
 
-var knownPlanJSONFields = []string{
+var knownPlanTopLevelJSONFields = []string{
 	"title",
 	"body",
 	"tasks",
-	"after",
 }
 
 // PlanInput is the JSON schema for `ergo plan`.
@@ -61,7 +60,7 @@ func ParsePlanInput() (*PlanInput, *ValidationError) {
 			invalid := map[string]string{
 				unknownField: "unknown field",
 			}
-			if suggestion, ok := suggestFieldNameFrom(unknownField, knownPlanJSONFields); ok {
+			if suggestion, ok := suggestFieldNameFrom(unknownField, knownPlanTopLevelJSONFields); ok {
 				message = fmt.Sprintf("invalid JSON: unknown field %q (did you mean: %s?)", unknownField, suggestion)
 				invalid[unknownField] = fmt.Sprintf("unknown field (did you mean: %s?)", suggestion)
 			}
diff --git a/internal/ergo/plan_input_test.go b/internal/ergo/plan_input_test.go
index c538fbc..6731d11 100644
--- a/internal/ergo/plan_input_test.go
+++ b/internal/ergo/plan_input_test.go
@@ -45,6 +45,22 @@ func TestParsePlanInput_RejectsUnknownNestedField_WithSuggestion(t *testing.T) {
 	}
 }
 
+func TestParsePlanInput_UnknownTopLevelDoesNotSuggestNestedField(t *testing.T) {
+	restoreStdin := setStdin(t, `{"title":"Epic","tasks":[{"title":"A"}],"aftr":"x"}`)
+	defer restoreStdin()
+
+	_, err := ParsePlanInput()
+	if err == nil {
+		t.Fatal("expected parse error for unknown field, got nil")
+	}
+	if err.Error != "parse_error" {
+		t.Fatalf("expected parse_error, got %q", err.Error)
+	}
+	if strings.Contains(err.Message, "did you mean: after") {
+		t.Fatalf("expected no suggestion for nested-only field, got %q", err.Message)
+	}
+}
+
 func TestParsePlanInput_RejectsMultipleJSONValues(t *testing.T) {
 	restoreStdin := setStdin(t, `{"title":"Epic","tasks":[{"title":"A"}]}{"title":"Extra"}`)
 	defer restoreStdin()