diff --git a/src/utils/typeValidation.ts b/src/utils/typeValidation.ts
index 1ec95392..478fe643 100644
--- a/src/utils/typeValidation.ts
+++ b/src/utils/typeValidation.ts
@@ -1,3 +1,11 @@
+/**
+ * @module utils/typeValidation
+ * @description O(1) runtime validation for the {@link NounType} / {@link VerbType}
+ * enums. Precomputes a `Set` of each enum's values once at module load, then
+ * exposes type-guard predicates (`isValidNounType` / `isValidVerbType`) and their
+ * throwing counterparts used by the write-path parameter validators. Pure and
+ * side-effect-free apart from the two module-level lookup sets.
+ */
 import { NounType, VerbType } from '../types/graphTypes.js'
 
 // Type sets for O(1) validation