diff --git a/modules/mesh-delivery-indexer/internal/index/views.go b/modules/mesh-delivery-indexer/internal/index/views.go
index 07fdf8d3..777d28f2 100644
--- a/modules/mesh-delivery-indexer/internal/index/views.go
+++ b/modules/mesh-delivery-indexer/internal/index/views.go
@@ -35,6 +35,7 @@ var ReadTools = []ViewedTool{
 	{Tool: "indexer_read_heard", State: HeardState, Words: "the forge messages the indexer heard and what it did with each."},
 	{Tool: "indexer_read_taken", State: "taken", Words: "each repository's merge the indexer took in last."},
 	{Tool: "indexer_read_findings", State: health.FindingsState, Words: "the indexer's findings, which the condition keeper raises and clears."},
+	{Tool: "indexer_read_seat_definitions", State: SeatDefinitionsState, Words: "the seat definitions the trunk's and each open pull request's contracts modules hold, resolved, or why one does not parse."},
 }
 
 // ViewedTool is one tool over one state of the indexer's.
diff --git a/modules/mesh-delivery-indexer/manifest_test.go b/modules/mesh-delivery-indexer/manifest_test.go
index 55aac124..f64a1b30 100644
--- a/modules/mesh-delivery-indexer/manifest_test.go
+++ b/modules/mesh-delivery-indexer/manifest_test.go
@@ -143,7 +143,7 @@ func TestManifestDeclarations(t *testing.T) { // 1238/AC1, 1444 (reads the build
 	// 1945: indexer_take_in, served by its tools bundle through the takeins state; the process serves none. The same bundle
 	// reads the verdicts state (indexer_verdicts) and asks the indexer to judge again through the takeins state
 	// (indexer_judge; issue 774, clause 3). 1966/AC11: indexer_old_sections reads the count of the old sections (state oldsections).
-	// ADR 0621 §1, ADR 0622 §1: the first-view tools manifests, modules and verdicts, and design 25 § 12.2's nine read
+	// ADR 0621 §1, ADR 0622 §1: the first-view tools manifests, modules and verdicts, and design 25 § 12.2's read
 	// tools, all of the tools bundle, which runs in a runtime of its own on the indexer's account (runs-as).
 	want := []string{"indexer_take_in", "indexer_old_sections", "indexer_verdicts", "indexer_judge"}
 	for _, v := range append(append([]index.ViewedTool{}, index.FirstViewTools...), index.ReadTools...) {
@@ -154,9 +154,29 @@ func TestManifestDeclarations(t *testing.T) { // 1238/AC1, 1444 (reads the build
 	}
 	want = append(want, "indexer_first_views", "indexer_first_view_again", index.ConfigReadersTool, index.BusStateTool, index.RequirementsTool, index.PackageUsersTool, index.SayAcceptedTool, // DLV-F3r, DLV-I10, DLV-I11, DLV-I7, DLV-I8, DLV-I9c
 		index.SeatDefinitionTool, index.SeatDefinitionsAgainTool, index.OutOfStepTool) // DLV-I19
-	if !reflect.DeepEqual(m.Tools, want) || len(want) != 27 {
+	if !reflect.DeepEqual(m.Tools, want) || len(want) != 28 {
 		t.Errorf("tools = %v, want %v", m.Tools, want)
 	}
+	// Every read tool of the indexer a reader of this repository invokes is one it serves (the checker's seventh first
+	// view, indexer_read_seat_definitions, was invoked and not served).
+	readers, _ := filepath.Glob("../*/module.json")
+	for _, p := range readers {
+		raw, err := os.ReadFile(p)
+		if err != nil {
+			t.Fatal(err)
+		}
+		var r struct {
+			Invokes []string `json:"invokes"`
+		}
+		if err := json.Unmarshal(raw, &r); err != nil {
+			t.Fatalf("%s: %v", p, err)
+		}
+		for _, inv := range r.Invokes {
+			if tool, ok := strings.CutPrefix(inv, "mesh-delivery-indexer."); ok && !slices.Contains(m.Tools, tool) {
+				t.Errorf("%s invokes %s, which the indexer does not serve", p, inv)
+			}
+		}
+	}
 	if m.RunsAs != m.Module || m.SecretsOwner != m.RunsAs {
 		t.Errorf("runs-as = %q, secrets-owner %q: the tools bundle runs on the indexer's own account (ADR 0621 §1)", m.RunsAs, m.SecretsOwner)
 	}
diff --git a/modules/mesh-delivery-indexer/module.json b/modules/mesh-delivery-indexer/module.json
index b31db3e5..ce436d7a 100644
--- a/modules/mesh-delivery-indexer/module.json
+++ b/modules/mesh-delivery-indexer/module.json
@@ -33,6 +33,7 @@
     "indexer_read_heard",
     "indexer_read_taken",
     "indexer_read_findings",
+    "indexer_read_seat_definitions",
     "indexer_first_views",
     "indexer_first_view_again",
     "indexer_config_readers",