diff --git a/scripts/check-deadcode-unused-files.mjs b/scripts/check-deadcode-unused-files.mjs
index cb3fe93c33b8..969b4f6709d6 100644
--- a/scripts/check-deadcode-unused-files.mjs
+++ b/scripts/check-deadcode-unused-files.mjs
@@ -1,4 +1,5 @@
 #!/usr/bin/env node
+// Runs knip unused-file detection and compares results to the allowlist.
 import { spawn } from "node:child_process";
 import { fileURLToPath } from "node:url";
 import {
@@ -8,9 +9,21 @@ import {
 import { createPnpmRunnerSpawnSpec } from "./pnpm-runner.mjs";
 
 const KNIP_VERSION = "6.8.0";
+/**
+ * Timeout for the unused-file knip child process.
+ */
 export const KNIP_TIMEOUT_MS = 10 * 60 * 1000;
+/**
+ * Grace period before force-killing a timed-out knip child process.
+ */
 export const KNIP_KILL_GRACE_MS = 5_000;
+/**
+ * Heartbeat interval used while knip runs without output.
+ */
 export const KNIP_HEARTBEAT_MS = 60_000;
+/**
+ * Maximum buffered knip output retained for diagnostics.
+ */
 export const KNIP_MAX_BUFFER_BYTES = 16 * 1024 * 1024;
 const KNIP_ARGS = [
   "--config",
@@ -37,6 +50,9 @@ function isLikelyRepoFilePath(value) {
   return /^(apps|docs|extensions|packages|scripts|src|test|ui)\//u.test(normalizeRepoPath(value));
 }
 
+/**
+ * Parses compact knip output into unused file paths.
+ */
 export function parseKnipCompactUnusedFiles(output) {
   const files = [];
   let inUnusedFilesSection = false;
@@ -68,6 +84,9 @@ export function parseKnipCompactUnusedFiles(output) {
   return uniqueSorted(files);
 }
 
+/**
+ * Compares detected unused files against the checked-in allowlist.
+ */
 export function compareUnusedFilesToAllowlist(
   actualFiles,
   allowlistFiles,
@@ -90,6 +109,9 @@ export function compareUnusedFilesToAllowlist(
   };
 }
 
+/**
+ * Formats unused-file allowlist drift for CLI output.
+ */
 export function formatUnusedFileComparison(comparison) {
   const lines = [];
   if (!comparison.allowlistIsSorted) {
@@ -132,6 +154,9 @@ function signalProcessTree(child, signal) {
   }
 }
 
+/**
+ * Runs knip and returns parsed unused-file results.
+ */
 export async function runKnipUnusedFiles(params = {}) {
   const run = params.spawnCommand ?? spawn;
   const timeoutMs = params.timeoutMs ?? KNIP_TIMEOUT_MS;
@@ -284,6 +309,9 @@ export async function runKnipUnusedFiles(params = {}) {
     });
   });
 }
+/**
+ * Checks detected unused files against the current allowlist.
+ */
 export function checkUnusedFiles(
   output,
   allowlistFiles = KNIP_UNUSED_FILE_ALLOWLIST,
diff --git a/scripts/check-dependency-pins.mjs b/scripts/check-dependency-pins.mjs
index daf7c1ed3119..3bcc278d79f8 100644
--- a/scripts/check-dependency-pins.mjs
+++ b/scripts/check-dependency-pins.mjs
@@ -1,5 +1,6 @@
 #!/usr/bin/env node
 
+// Audits patched dependency pins for exact versions and drift.
 import { execFileSync } from "node:child_process";
 import fs from "node:fs";
 import path from "node:path";
@@ -106,10 +107,16 @@ function collectWorkspaceViolations(cwd) {
   return violations;
 }
 
+/**
+ * Collects dependency pin violations for the current workspace.
+ */
 export function collectDependencyPinViolations(cwd = process.cwd()) {
   return [...collectPackageJsonViolations(cwd), ...collectWorkspaceViolations(cwd)];
 }
 
+/**
+ * Builds the full dependency pin audit payload.
+ */
 export function collectDependencyPinAudit(cwd = process.cwd()) {
   const packageJsonFiles = listTrackedPackageJsonFiles(cwd);
   let packageSpecCount = 0;
@@ -128,6 +135,9 @@ export function collectDependencyPinAudit(cwd = process.cwd()) {
   };
 }
 
+/**
+ * Runs the dependency pin check.
+ */
 export async function main() {
   const audit = collectDependencyPinAudit();
   const { violations } = audit;
diff --git a/scripts/check-deprecated-api-usage.mjs b/scripts/check-deprecated-api-usage.mjs
index 82c758d27d2a..be258f3f2ba6 100644
--- a/scripts/check-deprecated-api-usage.mjs
+++ b/scripts/check-deprecated-api-usage.mjs
@@ -1,4 +1,5 @@
 #!/usr/bin/env node
+// Scans source files for usage of deprecated API markers.
 import fs from "node:fs";
 import path from "node:path";
 import { collectDeprecatedInternalConfigApiViolations } from "./lib/deprecated-config-api-guard.mjs";
diff --git a/scripts/check-deprecated-jsdoc.mjs b/scripts/check-deprecated-jsdoc.mjs
index 96bd204f7357..c1a7d86e72ec 100644
--- a/scripts/check-deprecated-jsdoc.mjs
+++ b/scripts/check-deprecated-jsdoc.mjs
@@ -1,4 +1,5 @@
 #!/usr/bin/env node
+// Checks deprecated JSDoc blocks for required migration details.
 import fs from "node:fs";
 import { createRequire } from "node:module";
 import path from "node:path";
diff --git a/scripts/check-docs-i18n-glossary.mjs b/scripts/check-docs-i18n-glossary.mjs
index 96f890bc4ff5..28ae5f0befe3 100644
--- a/scripts/check-docs-i18n-glossary.mjs
+++ b/scripts/check-docs-i18n-glossary.mjs
@@ -1,5 +1,6 @@
 #!/usr/bin/env node
 
+// Validates docs i18n glossary terms against configured usage rules.
 import { execFileSync } from "node:child_process";
 import fs from "node:fs";
 import path from "node:path";
diff --git a/scripts/check-docs-mdx.mjs b/scripts/check-docs-mdx.mjs
index e6892c797de0..9015e09dcc8a 100644
--- a/scripts/check-docs-mdx.mjs
+++ b/scripts/check-docs-mdx.mjs
@@ -1,5 +1,6 @@
 #!/usr/bin/env node
 
+// Validates docs MDX files for syntax and repository-specific conventions.
 import fs from "node:fs";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
@@ -91,6 +92,9 @@ function parsePositiveIntegerArg(raw, label) {
   return value;
 }
 
+/**
+ * Parses docs MDX check arguments.
+ */
 export function parseArgs(argv) {
   const roots = [];
   let jsonOut = "";
diff --git a/scripts/check-duplicates.mjs b/scripts/check-duplicates.mjs
index c86418779713..95d255ea4960 100644
--- a/scripts/check-duplicates.mjs
+++ b/scripts/check-duplicates.mjs
@@ -1,4 +1,5 @@
 #!/usr/bin/env node
+// Runs duplicate-code detection with repo-specific excludes.
 import { spawnSync } from "node:child_process";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
diff --git a/scripts/check-dynamic-import-warts.mjs b/scripts/check-dynamic-import-warts.mjs
index 7a19b700afc8..0a9badfbd8bd 100644
--- a/scripts/check-dynamic-import-warts.mjs
+++ b/scripts/check-dynamic-import-warts.mjs
@@ -1,5 +1,6 @@
 #!/usr/bin/env node
 
+// Advises on ineffective or suspicious dynamic import patterns.
 import { promises as fs } from "node:fs";
 import path from "node:path";
 import ts from "typescript";
@@ -90,6 +91,9 @@ function isIgnoredTestHelperPath(filePath) {
   );
 }
 
+/**
+ * Finds dynamic import advisories in a single source file.
+ */
 export function findDynamicImportAdvisories(content, fileName = "source.ts") {
   const sourceFile = ts.createSourceFile(fileName, content, ts.ScriptTarget.Latest, true);
   const staticRuntimeImports = new Map();
@@ -171,6 +175,9 @@ export function findDynamicImportAdvisories(content, fileName = "source.ts") {
   return advisories;
 }
 
+/**
+ * Collects dynamic import advisories across configured source roots.
+ */
 export async function collectDynamicImportAdvisories(options = {}) {
   const roots = options.roots ?? defaultRoots;
   const files = await collectTypeScriptFilesFromRoots(roots, {
@@ -195,6 +202,9 @@ export async function collectDynamicImportAdvisories(options = {}) {
   return advisories;
 }
 
+/**
+ * Runs the dynamic import advisory check.
+ */
 export async function main(argv = process.argv.slice(2)) {
   const fail = argv.includes("--fail");
   const json = argv.includes("--json");
diff --git a/scripts/check-extension-package-tsc-boundary.mjs b/scripts/check-extension-package-tsc-boundary.mjs
index 86f844da5172..8928098d7ddb 100644
--- a/scripts/check-extension-package-tsc-boundary.mjs
+++ b/scripts/check-extension-package-tsc-boundary.mjs
@@ -1,5 +1,6 @@
 #!/usr/bin/env node
 
+// Verifies extension packages compile through their package-local TypeScript boundary.
 import { spawn, spawnSync } from "node:child_process";
 import {
   existsSync,
@@ -49,6 +50,9 @@ function parseMode(argv) {
   return mode;
 }
 
+/**
+ * Resolves the compile worker count from CLI/env/default settings.
+ */
 export function resolveCompileConcurrency(
   env = process.env,
   availableParallelism = os.availableParallelism(),
@@ -98,6 +102,9 @@ function createStepOutputCapture() {
   return { text: "", truncatedChars: 0 };
 }
 
+/**
+ * Appends child-process output while preserving only the diagnostic tail.
+ */
 export function appendBoundedStepOutput(buffer, chunk, maxChars = STEP_OUTPUT_MAX_CHARS) {
   const nextText = buffer.text + String(chunk);
   if (nextText.length <= maxChars) {
@@ -114,6 +121,9 @@ function formatCapturedStepOutput(buffer) {
   return `[output truncated ${buffer.truncatedChars} chars; showing tail]\n${buffer.text}`;
 }
 
+/**
+ * Formats the successful boundary compile summary.
+ */
 export function formatBoundaryCheckSuccessSummary(params = {}) {
   const lines = ["extension package boundary check passed"];
   if (params.mode) {
@@ -143,6 +153,9 @@ export function formatBoundaryCheckSuccessSummary(params = {}) {
   return `${lines.join("\n")}\n`;
 }
 
+/**
+ * Formats skipped compile progress for fresh extension canaries.
+ */
 export function formatSkippedCompileProgress(params = {}) {
   const skippedCount = params.skippedCount ?? 0;
   const totalCount = params.totalCount ?? 0;
@@ -157,6 +170,9 @@ export function formatSkippedCompileProgress(params = {}) {
   return `skipped ${skippedCount} fresh plugin compiles\n`;
 }
 
+/**
+ * Formats slow extension compile diagnostics.
+ */
 export function formatSlowCompileSummary(params = {}) {
   const compileTimings = Array.isArray(params.compileTimings) ? params.compileTimings : [];
   if (compileTimings.length === 0) {
@@ -174,6 +190,9 @@ export function formatSlowCompileSummary(params = {}) {
   return `${lines.join("\n")}\n`;
 }
 
+/**
+ * Formats a failed boundary-check child process step.
+ */
 export function formatStepFailure(label, params = {}) {
   const stdoutSection = summarizeOutputSection("stdout", params.stdout ?? "");
   const stderrSection = summarizeOutputSection("stderr", params.stderr ?? "");
@@ -285,6 +304,9 @@ function collectOldestMtime(paths) {
   return Number.isFinite(oldestMtimeMs) ? oldestMtimeMs : null;
 }
 
+/**
+ * Checks whether an extension boundary compile canary is still fresh.
+ */
 export function isBoundaryCompileFresh(extensionId, params = {}) {
   const rootDir = params.rootDir ?? repoRoot;
   const extensionRoot = resolve(rootDir, "extensions", extensionId);
@@ -363,6 +385,9 @@ function abortSiblingSteps(abortController) {
   }
 }
 
+/**
+ * Runs one node-based boundary check step with timeout and output capture.
+ */
 export function runNodeStepAsync(label, args, timeoutMs, params = {}) {
   const abortController = params.abortController;
   const killProcess = params.killProcess ?? process.kill.bind(process);
@@ -540,6 +565,9 @@ export function runNodeStepAsync(label, args, timeoutMs, params = {}) {
   });
 }
 
+/**
+ * Runs boundary check steps with bounded concurrency.
+ */
 export async function runNodeStepsWithConcurrency(steps, concurrency) {
   const abortController = new AbortController();
   let firstFailure = null;
@@ -571,6 +599,9 @@ export async function runNodeStepsWithConcurrency(steps, concurrency) {
   }
 }
 
+/**
+ * Resolves canary artifact paths for an extension boundary compile.
+ */
 export function resolveCanaryArtifactPaths(extensionId, rootDir = repoRoot) {
   const extensionRoot = resolve(rootDir, "extensions", extensionId);
   return {
@@ -580,18 +611,27 @@ export function resolveCanaryArtifactPaths(extensionId, rootDir = repoRoot) {
   };
 }
 
+/**
+ * Removes canary artifacts for one extension.
+ */
 export function cleanupCanaryArtifacts(extensionId, rootDir = repoRoot) {
   const { canaryPath, tsconfigPath } = resolveCanaryArtifactPaths(extensionId, rootDir);
   rmSync(canaryPath, { force: true });
   rmSync(tsconfigPath, { force: true });
 }
 
+/**
+ * Removes canary artifacts for multiple extensions.
+ */
 export function cleanupCanaryArtifactsForExtensions(extensionIds, rootDir = repoRoot) {
   for (const extensionId of extensionIds) {
     cleanupCanaryArtifacts(extensionId, rootDir);
   }
 }
 
+/**
+ * Installs signal/exit cleanup for extension canary artifacts.
+ */
 export function installCanaryArtifactCleanup(extensionIds, params = {}) {
   const rootDir = params.rootDir ?? repoRoot;
   const processObject = params.processObject ?? process;
@@ -612,6 +652,9 @@ function resolveBoundaryTsStampPath(extensionId, rootDir = repoRoot) {
   return resolve(rootDir, "extensions", extensionId, "dist", ".boundary-tsc.stamp");
 }
 
+/**
+ * Resolves the local lock path for extension boundary checks.
+ */
 export function resolveBoundaryCheckLockPath(rootDir = repoRoot) {
   return resolve(rootDir, "dist", ".extension-package-boundary.lock");
 }
@@ -649,6 +692,9 @@ function removeStaleBoundaryCheckLock(lockPath) {
   return true;
 }
 
+/**
+ * Acquires the single-process lock for extension boundary checks.
+ */
 export function acquireBoundaryCheckLock(params = {}) {
   const rootDir = params.rootDir ?? repoRoot;
   const processObject = params.processObject ?? process;
@@ -848,6 +894,9 @@ async function runCanaryCheck(extensionIds) {
   };
 }
 
+/**
+ * Runs the extension package TypeScript boundary check.
+ */
 export async function main(argv = process.argv.slice(2)) {
   const startedAt = Date.now();
   const mode = parseMode(argv);
diff --git a/scripts/check-extension-plugin-sdk-boundary.mjs b/scripts/check-extension-plugin-sdk-boundary.mjs
index a6372a2a60b8..f6ee00a944f7 100644
--- a/scripts/check-extension-plugin-sdk-boundary.mjs
+++ b/scripts/check-extension-plugin-sdk-boundary.mjs
@@ -1,5 +1,6 @@
 #!/usr/bin/env node
 
+// Inventories extension imports to enforce plugin SDK boundary rules.
 import { promises as fs } from "node:fs";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
@@ -225,6 +226,9 @@ function collectEntriesByModeFromModuleReferences(filePath, references) {
   return entriesByMode;
 }
 
+/**
+ * Collects the current extension plugin SDK boundary inventory.
+ */
 export async function collectExtensionPluginSdkBoundaryInventory(mode) {
   if (!MODES.has(mode)) {
     throw new Error(`Unknown mode: ${mode}`);
@@ -253,6 +257,9 @@ export async function collectExtensionPluginSdkBoundaryInventory(mode) {
   return inventoryByMode[mode];
 }
 
+/**
+ * Reads the checked-in expected boundary inventory.
+ */
 export async function readExpectedInventory(mode) {
   try {
     return JSON.parse(await fs.readFile(baselinePathByMode[mode], "utf8"));
@@ -270,6 +277,9 @@ export async function readExpectedInventory(mode) {
   }
 }
 
+/**
+ * Diffs expected and actual boundary inventory entries.
+ */
 export function diffInventory(expected, actual) {
   return diffInventoryEntries(expected, actual, compareEntries);
 }
@@ -294,6 +304,9 @@ function formatInventoryHuman(mode, inventory) {
   return lines.join("\n");
 }
 
+/**
+ * Runs the boundary inventory check with CLI-style inputs and outputs.
+ */
 export async function runExtensionPluginSdkBoundaryCheck(argv, io) {
   const args = argv ?? process.argv.slice(2);
   const streams = io ?? { stdout: process.stdout, stderr: process.stderr };
@@ -343,6 +356,9 @@ export async function runExtensionPluginSdkBoundaryCheck(argv, io) {
   return 1;
 }
 
+/**
+ * Entrypoint wrapper for the extension plugin SDK boundary check.
+ */
 export async function main(argv, io) {
   const exitCode = await runExtensionPluginSdkBoundaryCheck(argv, io);
   if (!io) {