diff --git a/crates/ailang-core/src/ast.rs b/crates/ailang-core/src/ast.rs
index 175c390..84abff3 100644
--- a/crates/ailang-core/src/ast.rs
+++ b/crates/ailang-core/src/ast.rs
@@ -565,8 +565,8 @@ mod hex_u64 {
 ///
 /// The JSON discriminator is the `kind` field. `Unit` carries no
 /// payload and serializes as `{"kind":"unit"}`. `Float` carries a
-/// `u64` IEEE-754 binary64 bit pattern, serialized via the
-/// [`hex_u64`] helper as a 16-character lowercase hex string —
+/// `u64` IEEE-754 binary64 bit pattern, serialized via a private
+/// `hex_u64` helper as a 16-character lowercase hex string —
 /// canonical-JSON bytes therefore stay bit-stable for hashing and
 /// can represent NaN / ±Inf (which JSON numbers cannot).
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -581,7 +581,8 @@ pub enum Literal {
     /// The unit value `()`.
     Unit,
     /// IEEE-754 binary64 (LLVM `double`) carried as its bit pattern.
-    /// See [`hex_u64`] for the serialization rationale.
+    /// The private `hex_u64` helper module above documents why the
+    /// field is routed through the JSON string path.
     Float {
         #[serde(with = "hex_u64")]
         bits: u64,