diff --git a/.changeset/palette-jsdoc-fix.md b/.changeset/palette-jsdoc-fix.md
new file mode 100644
index 00000000..e912698e
--- /dev/null
+++ b/.changeset/palette-jsdoc-fix.md
@@ -0,0 +1,5 @@
+---
+"node-version": patch
+---
+
+Improve JSDoc for version comparison methods to clarify invalid input handling and strictness of `is()` method.
diff --git a/.jules/palette.md b/.jules/palette.md
new file mode 100644
index 00000000..799f4f2c
--- /dev/null
+++ b/.jules/palette.md
@@ -0,0 +1,5 @@
+# Palette Journal
+
+## 2026-01-03 - Initial Setup
+**Learning:** For utility libraries, UX often means DX (Developer Experience). Clear documentation of edge cases (like invalid inputs or strict vs loose comparison) prevents developer frustration.
+**Action:** Always check if "fail-closed" or "strict" behaviors are explicitly documented in JSDoc.
diff --git a/src/types.ts b/src/types.ts
index 4de06674..6bb8dc91 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -35,13 +35,14 @@ export interface NodeVersion {
     /**
      * Check if the current Node version is at least the specified version.
      * @param version The version to compare against (e.g., '20.0.0').
-     * @returns {boolean} True if current version >= target version.
+     * @returns {boolean} True if current version >= target version. Returns false for invalid version strings.
      * @example
      * version.isAtLeast('18.0.0'); // true if current is 20.0.0
      */
     isAtLeast(version: string): boolean;
     /**
      * Check if the current Node version matches the specified version.
+     * Note: This method performs a strict string equality check and does not normalize inputs (e.g., 'v' prefix).
      * @param version The version to compare against (e.g., '20.0.0').
      * @returns {boolean} True if current version === target version.
      * @example
@@ -51,7 +52,7 @@ export interface NodeVersion {
     /**
      * Check if the current Node version is strictly greater than the specified version.
      * @param version The version to compare against (e.g., '20.0.0').
-     * @returns {boolean} True if current version > target version.
+     * @returns {boolean} True if current version > target version. Returns false for invalid version strings.
      * @example
      * version.isAbove('18.0.0'); // true if current is 20.0.0
      */
@@ -59,7 +60,7 @@ export interface NodeVersion {
     /**
      * Check if the current Node version is strictly less than the specified version.
      * @param version The version to compare against (e.g., '20.0.0').
-     * @returns {boolean} True if current version < target version.
+     * @returns {boolean} True if current version < target version. Returns false for invalid version strings.
      * @example
      * version.isBelow('22.0.0'); // true if current is 20.0.0
      */
@@ -67,7 +68,7 @@ export interface NodeVersion {
     /**
      * Check if the current Node version is at most the specified version.
      * @param version The version to compare against (e.g., '20.0.0').
-     * @returns {boolean} True if current version <= target version.
+     * @returns {boolean} True if current version <= target version. Returns false for invalid version strings.
      * @example
      * version.isAtMost('22.0.0'); // true if current is 20.0.0
      */