diff --git a/lib/internal/modules/esm/resolve.js b/lib/internal/modules/esm/resolve.js
index 8b6f23bb485d8b..0a0da107682469 100644
--- a/lib/internal/modules/esm/resolve.js
+++ b/lib/internal/modules/esm/resolve.js
@@ -59,7 +59,26 @@ const userConditions = getOptionValue('--conditions');
 const DEFAULT_CONDITIONS = ObjectFreeze(['node', 'import', ...userConditions]);
 const DEFAULT_CONDITIONS_SET = new SafeSet(DEFAULT_CONDITIONS);
 
+/**
+ * @typedef {string | string[] | Record<string, unknown>} Exports
+ * @typedef {'module' | 'commonjs'} PackageType
+ * @typedef {{
+ *   exports?: ExportConfig;
+ *   name?: string;
+ *   main?: string;
+ *   type?: PackageType;
+ * }} PackageConfig
+ */
+
 const emittedPackageWarnings = new SafeSet();
+
+/**
+ * @param {string} match
+ * @param {URL} pjsonUrl
+ * @param {boolean} isExports
+ * @param {string | URL | undefined} base
+ * @returns {void}
+ */
 function emitFolderMapDeprecation(match, pjsonUrl, isExports, base) {
   const pjsonPath = fileURLToPath(pjsonUrl);
 
@@ -76,6 +95,13 @@ function emitFolderMapDeprecation(match, pjsonUrl, isExports, base) {
   );
 }
 
+/**
+ * @param {URL} url
+ * @param {URL} packageJSONUrl
+ * @param {string | URL | undefined} base
+ * @param {string} main
+ * @returns
+ */
 function emitLegacyIndexDeprecation(url, packageJSONUrl, base, main) {
   const { format } = defaultGetFormat(url);
   if (format !== 'module')
@@ -104,6 +130,10 @@ function emitLegacyIndexDeprecation(url, packageJSONUrl, base, main) {
     );
 }
 
+/**
+ * @param {string[]} [conditions]
+ * @returns {Set<string>}
+ */
 function getConditionsSet(conditions) {
   if (conditions !== undefined && conditions !== DEFAULT_CONDITIONS) {
     if (!ArrayIsArray(conditions)) {
@@ -118,9 +148,19 @@ function getConditionsSet(conditions) {
 const realpathCache = new SafeMap();
 const packageJSONCache = new SafeMap();  /* string -> PackageConfig */
 
+/**
+ * @param {string | URL} path
+ * @returns {import('fs').Stats}
+ */
 const tryStatSync =
   (path) => statSync(path, { throwIfNoEntry: false }) ?? new Stats();
 
+/**
+ * @param {string} path
+ * @param {string} specifier
+ * @param {string | URL | undefined} base
+ * @returns {PackageConfig}
+ */
 function getPackageConfig(path, specifier, base) {
   const existing = packageJSONCache.get(path);
   if (existing !== undefined) {
@@ -173,6 +213,10 @@ function getPackageConfig(path, specifier, base) {
   return packageConfig;
 }
 
+/**
+ * @param {URL | string} resolved
+ * @returns {PackageConfig}
+ */
 function getPackageScopeConfig(resolved) {
   let packageJSONUrl = new URL('./package.json', resolved);
   while (true) {
@@ -205,12 +249,6 @@ function getPackageScopeConfig(resolved) {
 }
 
 /**
- * Legacy CommonJS main resolution:
- * 1. let M = pkg_url + (json main field)
- * 2. TRY(M, M.js, M.json, M.node)
- * 3. TRY(M/index.js, M/index.json, M/index.node)
- * 4. TRY(pkg_url/index.js, pkg_url/index.json, pkg_url/index.node)
- * 5. NOT_FOUND
  * @param {string | URL} url
  * @returns {boolean}
  */
@@ -218,6 +256,18 @@ function fileExists(url) {
   return statSync(url, { throwIfNoEntry: false })?.isFile() ?? false;
 }
 
+/**
+ * Legacy CommonJS main resolution:
+ * 1. let M = pkg_url + (json main field)
+ * 2. TRY(M, M.js, M.json, M.node)
+ * 3. TRY(M/index.js, M/index.json, M/index.node)
+ * 4. TRY(pkg_url/index.js, pkg_url/index.json, pkg_url/index.node)
+ * 5. NOT_FOUND
+ * @param {URL} packageJSONUrl
+ * @param {PackageConfig} packageConfig
+ * @param {string | URL | undefined} base
+ * @returns {URL}
+ */
 function legacyMainResolve(packageJSONUrl, packageConfig, base) {
   let guess;
   if (packageConfig.main !== undefined) {
@@ -259,12 +309,21 @@ function legacyMainResolve(packageJSONUrl, packageConfig, base) {
     fileURLToPath(new URL('.', packageJSONUrl)), fileURLToPath(base));
 }
 
+/**
+ * @param {URL} search
+ * @returns {URL | undefined}
+ */
 function resolveExtensionsWithTryExactName(search) {
   if (fileExists(search)) return search;
   return resolveExtensions(search);
 }
 
 const extensions = ['.js', '.json', '.node', '.mjs'];
+
+/**
+ * @param {URL} search
+ * @returns {URL | undefined}
+ */
 function resolveExtensions(search) {
   for (let i = 0; i < extensions.length; i++) {
     const extension = extensions[i];
@@ -274,6 +333,10 @@ function resolveExtensions(search) {
   return undefined;
 }
 
+/**
+ * @param {URL} search
+ * @returns {URL | undefined}
+ */
 function resolveDirectoryEntry(search) {
   const dirPath = fileURLToPath(search);
   const pkgJsonPath = resolve(dirPath, 'package.json');
@@ -291,6 +354,11 @@ function resolveDirectoryEntry(search) {
 }
 
 const encodedSepRegEx = /%2F|%2C/i;
+/**
+ * @param {URL} resolved
+ * @param {string | URL | undefined} base
+ * @returns {URL | undefined}
+ */
 function finalizeResolution(resolved, base) {
   if (RegExpPrototypeTest(encodedSepRegEx, resolved.pathname))
     throw new ERR_INVALID_MODULE_SPECIFIER(
@@ -325,18 +393,35 @@ function finalizeResolution(resolved, base) {
   return resolved;
 }
 
+/**
+ * @param {string} specifier
+ * @param {URL} packageJSONUrl
+ * @param {string | URL | undefined} base
+ */
 function throwImportNotDefined(specifier, packageJSONUrl, base) {
   throw new ERR_PACKAGE_IMPORT_NOT_DEFINED(
     specifier, packageJSONUrl && fileURLToPath(new URL('.', packageJSONUrl)),
     fileURLToPath(base));
 }
 
+/**
+ * @param {string} specifier
+ * @param {URL} packageJSONUrl
+ * @param {string | URL | undefined} base
+ */
 function throwExportsNotFound(subpath, packageJSONUrl, base) {
   throw new ERR_PACKAGE_PATH_NOT_EXPORTED(
     fileURLToPath(new URL('.', packageJSONUrl)), subpath,
     base && fileURLToPath(base));
 }
 
+/**
+ *
+ * @param {string | URL} subpath
+ * @param {URL} packageJSONUrl
+ * @param {boolean} internal
+ * @param {string | URL | undefined} base
+ */
 function throwInvalidSubpath(subpath, packageJSONUrl, internal, base) {
   const reason = `request is not a valid subpath for the "${internal ?
     'imports' : 'exports'}" resolution of ${fileURLToPath(packageJSONUrl)}`;
@@ -478,6 +563,13 @@ function resolvePackageTarget(packageJSONUrl, target, subpath, packageSubpath,
                             base);
 }
 
+/**
+ *
+ * @param {Exports} exports
+ * @param {URL} packageJSONUrl
+ * @param {string | URL | undefined} base
+ * @returns
+ */
 function isConditionalExportsMainSugar(exports, packageJSONUrl, base) {
   if (typeof exports === 'string' || ArrayIsArray(exports)) return true;
   if (typeof exports !== 'object' || exports === null) return false;
@@ -504,8 +596,8 @@ function isConditionalExportsMainSugar(exports, packageJSONUrl, base) {
 /**
  * @param {URL} packageJSONUrl
  * @param {string} packageSubpath
- * @param {object} packageConfig
- * @param {string} base
+ * @param {PackageConfig} packageConfig
+ * @param {string | URL | undefined} base
  * @param {Set<string>} conditions
  * @returns {URL}
  */
@@ -560,6 +652,12 @@ function packageExportsResolve(
   throwExportsNotFound(packageSubpath, packageJSONUrl, base);
 }
 
+/**
+ * @param {string} name
+ * @param {string | URL | undefined} base
+ * @param {Set<string>} conditions
+ * @returns
+ */
 function packageImportsResolve(name, base, conditions) {
   if (name === '#' || StringPrototypeStartsWith(name, '#/')) {
     const reason = 'is not a valid internal imports specifier name';
@@ -615,11 +713,20 @@ function packageImportsResolve(name, base, conditions) {
   throwImportNotDefined(name, packageJSONUrl, base);
 }
 
+/**
+ * @param {URL} url
+ * @returns {PackageType}
+ */
 function getPackageType(url) {
   const packageConfig = getPackageScopeConfig(url);
   return packageConfig.type;
 }
 
+/**
+ * @param {string} specifier
+ * @param {string | URL | undefined} base
+ * @returns {{ packageName: string, packageSubpath: string, isScoped: boolean }}
+ */
 function parsePackageName(specifier, base) {
   let separatorIndex = StringPrototypeIndexOf(specifier, '/');
   let validPackageName = true;
@@ -659,7 +766,7 @@ function parsePackageName(specifier, base) {
 
 /**
  * @param {string} specifier
- * @param {URL} base
+ * @param {string | URL | undefined} base
  * @param {Set<string>} conditions
  * @returns {URL}
  */
@@ -712,6 +819,10 @@ function packageResolve(specifier, base, conditions) {
   throw new ERR_MODULE_NOT_FOUND(packageName, fileURLToPath(base));
 }
 
+/**
+ * @param {string} specifier
+ * @returns {boolean}
+ */
 function isBareSpecifier(specifier) {
   return specifier[0] && specifier[0] !== '/' && specifier[0] !== '.';
 }
@@ -734,7 +845,7 @@ function shouldBeTreatedAsRelativeOrAbsolutePath(specifier) {
 
 /**
  * @param {string} specifier
- * @param {URL} base
+ * @param {string | URL | undefined} base
  * @param {Set<string>} conditions
  * @returns {URL}
  */