diff --git a/tools/BUILD b/tools/BUILD
index a409958d8..2849bc919 100644
--- a/tools/BUILD
+++ b/tools/BUILD
@@ -51,6 +51,7 @@ cc_library(
         "@com_google_absl//absl/container:flat_hash_map",
         "@com_google_absl//absl/log:absl_check",
         "@com_google_absl//absl/memory",
+        "@com_google_absl//absl/strings:string_view",
         "@com_google_absl//absl/types:span",
         "@com_google_googleapis//google/api/expr/v1alpha1:checked_cc_proto",
         "@com_google_googleapis//google/api/expr/v1alpha1:syntax_cc_proto",
@@ -65,6 +66,8 @@ cc_test(
         "//base:builtins",
         "//internal:testing",
         "//parser",
+        "@com_google_absl//absl/base",
+        "@com_google_absl//absl/strings",
         "@com_google_googleapis//google/api/expr/v1alpha1:syntax_cc_proto",
     ],
 )
diff --git a/tools/navigable_ast.cc b/tools/navigable_ast.cc
index 368c366a1..afac5dac2 100644
--- a/tools/navigable_ast.cc
+++ b/tools/navigable_ast.cc
@@ -23,6 +23,7 @@
 #include "absl/container/flat_hash_map.h"
 #include "absl/log/absl_check.h"
 #include "absl/memory/memory.h"
+#include "absl/strings/string_view.h"
 #include "absl/types/span.h"
 #include "eval/public/ast_traverse.h"
 #include "eval/public/ast_visitor.h"
@@ -185,6 +186,64 @@ class NavigableExprBuilderVisitor
 
 }  // namespace
 
+absl::string_view ChildKindName(ChildKind kind) {
+  switch (kind) {
+    case ChildKind::kUnspecified:
+      return "Unspecified";
+    case ChildKind::kSelectOperand:
+      return "SelectOperand";
+    case ChildKind::kCallReceiver:
+      return "CallReceiver";
+    case ChildKind::kCallArg:
+      return "CallArg";
+    case ChildKind::kListElem:
+      return "ListElem";
+    case ChildKind::kMapKey:
+      return "MapKey";
+    case ChildKind::kMapValue:
+      return "MapValue";
+    case ChildKind::kStructValue:
+      return "StructValue";
+    case ChildKind::kComprehensionRange:
+      return "ComprehensionRange";
+    case ChildKind::kComprehensionInit:
+      return "ComprehensionInit";
+    case ChildKind::kComprehensionCondition:
+      return "ComprehensionCondition";
+    case ChildKind::kComprehensionLoopStep:
+      return "ComprehensionLoopStep";
+    case ChildKind::kComprensionResult:
+      return "ComprehensionResult";
+    default:
+      return "Unknown ChildKind";
+  }
+}
+
+absl::string_view NodeKindName(NodeKind kind) {
+  switch (kind) {
+    case NodeKind::kUnspecified:
+      return "Unspecified";
+    case NodeKind::kConstant:
+      return "Constant";
+    case NodeKind::kIdent:
+      return "Ident";
+    case NodeKind::kSelect:
+      return "Select";
+    case NodeKind::kCall:
+      return "Call";
+    case NodeKind::kList:
+      return "List";
+    case NodeKind::kMap:
+      return "Map";
+    case NodeKind::kStruct:
+      return "Struct";
+    case NodeKind::kComprehension:
+      return "Comprehension";
+    default:
+      return "Unknown NodeKind";
+  }
+}
+
 int AstNode::child_index() const {
   if (data_.parent == nullptr) {
     return -1;
diff --git a/tools/navigable_ast.h b/tools/navigable_ast.h
index 1a78bb70d..321866cbf 100644
--- a/tools/navigable_ast.h
+++ b/tools/navigable_ast.h
@@ -24,6 +24,7 @@
 #include "google/api/expr/v1alpha1/syntax.pb.h"
 #include "absl/base/nullability.h"
 #include "absl/container/flat_hash_map.h"
+#include "absl/strings/string_view.h"
 #include "absl/types/span.h"
 #include "tools/internal/navigable_ast_internal.h"
 
@@ -57,6 +58,20 @@ enum class NodeKind {
   kComprehension,
 };
 
+absl::string_view ChildKindName(ChildKind kind);
+
+template <typename Sink>
+void AbslStringify(Sink& sink, ChildKind kind) {
+  absl::Format(&sink, "%s", ChildKindName(kind));
+}
+
+absl::string_view NodeKindName(NodeKind kind);
+
+template <typename Sink>
+void AbslStringify(Sink& sink, NodeKind kind) {
+  absl::Format(&sink, "%s", NodeKindName(kind));
+}
+
 class AstNode;
 
 namespace tools_internal {
diff --git a/tools/navigable_ast_test.cc b/tools/navigable_ast_test.cc
index bb8a8a667..36b1379d8 100644
--- a/tools/navigable_ast_test.cc
+++ b/tools/navigable_ast_test.cc
@@ -18,6 +18,8 @@
 #include <vector>
 
 #include "google/api/expr/v1alpha1/syntax.pb.h"
+#include "absl/base/casts.h"
+#include "absl/strings/str_cat.h"
 #include "base/builtins.h"
 #include "internal/testing.h"
 #include "parser/parser.h"
@@ -340,5 +342,43 @@ TEST(NavigableAst, DescendantsPreorderCreateMap) {
                           Pair(NodeKind::kConstant, ChildKind::kMapValue)));
 }
 
+TEST(NodeKind, Stringify) {
+  // Note: the specific values are not important or guaranteed to be stable,
+  // they are only intended to make test outputs clearer.
+  EXPECT_EQ(absl::StrCat(NodeKind::kConstant), "Constant");
+  EXPECT_EQ(absl::StrCat(NodeKind::kIdent), "Ident");
+  EXPECT_EQ(absl::StrCat(NodeKind::kSelect), "Select");
+  EXPECT_EQ(absl::StrCat(NodeKind::kCall), "Call");
+  EXPECT_EQ(absl::StrCat(NodeKind::kList), "List");
+  EXPECT_EQ(absl::StrCat(NodeKind::kMap), "Map");
+  EXPECT_EQ(absl::StrCat(NodeKind::kStruct), "Struct");
+  EXPECT_EQ(absl::StrCat(NodeKind::kComprehension), "Comprehension");
+  EXPECT_EQ(absl::StrCat(NodeKind::kUnspecified), "Unspecified");
+
+  EXPECT_EQ(absl::StrCat(absl::bit_cast<NodeKind>(255)), "Unknown NodeKind");
+}
+
+TEST(ChildKind, Stringify) {
+  // Note: the specific values are not important or guaranteed to be stable,
+  // they are only intended to make test outputs clearer.
+  EXPECT_EQ(absl::StrCat(ChildKind::kSelectOperand), "SelectOperand");
+  EXPECT_EQ(absl::StrCat(ChildKind::kCallReceiver), "CallReceiver");
+  EXPECT_EQ(absl::StrCat(ChildKind::kCallArg), "CallArg");
+  EXPECT_EQ(absl::StrCat(ChildKind::kListElem), "ListElem");
+  EXPECT_EQ(absl::StrCat(ChildKind::kMapKey), "MapKey");
+  EXPECT_EQ(absl::StrCat(ChildKind::kMapValue), "MapValue");
+  EXPECT_EQ(absl::StrCat(ChildKind::kStructValue), "StructValue");
+  EXPECT_EQ(absl::StrCat(ChildKind::kComprehensionRange), "ComprehensionRange");
+  EXPECT_EQ(absl::StrCat(ChildKind::kComprehensionInit), "ComprehensionInit");
+  EXPECT_EQ(absl::StrCat(ChildKind::kComprehensionCondition),
+            "ComprehensionCondition");
+  EXPECT_EQ(absl::StrCat(ChildKind::kComprehensionLoopStep),
+            "ComprehensionLoopStep");
+  EXPECT_EQ(absl::StrCat(ChildKind::kComprensionResult), "ComprehensionResult");
+  EXPECT_EQ(absl::StrCat(ChildKind::kUnspecified), "Unspecified");
+
+  EXPECT_EQ(absl::StrCat(absl::bit_cast<ChildKind>(255)), "Unknown ChildKind");
+}
+
 }  // namespace
 }  // namespace cel