diff --git a/test/vitest/vitest.agents-paths.mjs b/test/vitest/vitest.agents-paths.mjs
index 0a4a9299d91d..cc9bd295e45d 100644
--- a/test/vitest/vitest.agents-paths.mjs
+++ b/test/vitest/vitest.agents-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing globs for agent core, embedded-agent, tool, and support suites.
 export const agentsAllTestPatterns = ["src/agents/**/*.test.ts"];
 
 export const agentsCoreTestPatterns = ["src/agents/*.test.ts"];
diff --git a/test/vitest/vitest.channel-paths.mjs b/test/vitest/vitest.channel-paths.mjs
index 489125618738..ee648b1e6d16 100644
--- a/test/vitest/vitest.channel-paths.mjs
+++ b/test/vitest/vitest.channel-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots and globs for core channel tests and channel plugin tests.
 import path from "node:path";
 import { BUNDLED_PLUGIN_PATH_PREFIX } from "../../scripts/lib/bundled-plugin-paths.mjs";
 import { splitChannelExtensionTestRoots } from "./vitest.extension-channel-split-paths.mjs";
diff --git a/test/vitest/vitest.commands-light-paths.mjs b/test/vitest/vitest.commands-light-paths.mjs
index 0f3192803840..1fdd0f535023 100644
--- a/test/vitest/vitest.commands-light-paths.mjs
+++ b/test/vitest/vitest.commands-light-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing map for lightweight command tests and their source triggers.
 const normalizeRepoPath = (value) => value.replaceAll("\\", "/");
 
 const commandsLightEntries = [
diff --git a/test/vitest/vitest.extension-acpx-paths.mjs b/test/vitest/vitest.extension-acpx-paths.mjs
index 0e69166dfb2c..09ab2b8577fd 100644
--- a/test/vitest/vitest.extension-acpx-paths.mjs
+++ b/test/vitest/vitest.extension-acpx-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for the ACP extension suite.
 export const acpxExtensionTestRoots = ["extensions/acpx"];
 
 export function isAcpxExtensionRoot(root) {
diff --git a/test/vitest/vitest.extension-active-memory-paths.mjs b/test/vitest/vitest.extension-active-memory-paths.mjs
index 34efcaa216fc..1e209ceb76bb 100644
--- a/test/vitest/vitest.extension-active-memory-paths.mjs
+++ b/test/vitest/vitest.extension-active-memory-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for active-memory extension tests.
 export const activeMemoryExtensionTestRoots = ["extensions/active-memory"];
 
 export function isActiveMemoryExtensionRoot(root) {
diff --git a/test/vitest/vitest.extension-browser-paths.mjs b/test/vitest/vitest.extension-browser-paths.mjs
index fe424535dac6..ea2d4ee31bd3 100644
--- a/test/vitest/vitest.extension-browser-paths.mjs
+++ b/test/vitest/vitest.extension-browser-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for browser extension tests.
 export const browserExtensionTestRoots = ["extensions/browser"];
 
 export function isBrowserExtensionRoot(root) {
diff --git a/test/vitest/vitest.extension-channel-split-paths.mjs b/test/vitest/vitest.extension-channel-split-paths.mjs
index 205927eeb99d..a7b95ffc26f7 100644
--- a/test/vitest/vitest.extension-channel-split-paths.mjs
+++ b/test/vitest/vitest.extension-channel-split-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing specs for channel plugins split into dedicated Vitest configs.
 import { bundledPluginRoot } from "../../scripts/lib/bundled-plugin-paths.mjs";
 
 export const splitChannelExtensionShardSpecs = [
diff --git a/test/vitest/vitest.extension-codex-paths.mjs b/test/vitest/vitest.extension-codex-paths.mjs
index 521c90d2558d..4ebe1d75e759 100644
--- a/test/vitest/vitest.extension-codex-paths.mjs
+++ b/test/vitest/vitest.extension-codex-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for Codex extension tests.
 export const codexExtensionTestRoots = ["extensions/codex"];
 
 export function isCodexExtensionRoot(root) {
diff --git a/test/vitest/vitest.extension-diffs-paths.mjs b/test/vitest/vitest.extension-diffs-paths.mjs
index 9559113ef01c..62440ac0b882 100644
--- a/test/vitest/vitest.extension-diffs-paths.mjs
+++ b/test/vitest/vitest.extension-diffs-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for diffs extension tests.
 export const diffsExtensionTestRoots = ["extensions/diffs"];
 
 export function isDiffsExtensionRoot(root) {
diff --git a/test/vitest/vitest.extension-feishu-paths.mjs b/test/vitest/vitest.extension-feishu-paths.mjs
index e61ef2a2cddf..36af38b7a5a9 100644
--- a/test/vitest/vitest.extension-feishu-paths.mjs
+++ b/test/vitest/vitest.extension-feishu-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for Feishu extension tests.
 import { bundledPluginRoot } from "../../scripts/lib/bundled-plugin-paths.mjs";
 
 export const feishuExtensionIds = ["feishu"];
diff --git a/test/vitest/vitest.extension-irc-paths.mjs b/test/vitest/vitest.extension-irc-paths.mjs
index 8ccb1daff339..744654d1e38b 100644
--- a/test/vitest/vitest.extension-irc-paths.mjs
+++ b/test/vitest/vitest.extension-irc-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for IRC extension tests.
 export const ircExtensionTestRoots = ["extensions/irc"];
 
 export function isIrcExtensionRoot(root) {
diff --git a/test/vitest/vitest.extension-matrix-paths.mjs b/test/vitest/vitest.extension-matrix-paths.mjs
index 5e8fd703f619..efb9bd50dca1 100644
--- a/test/vitest/vitest.extension-matrix-paths.mjs
+++ b/test/vitest/vitest.extension-matrix-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for Matrix extension tests.
 import { bundledPluginRoot } from "../../scripts/lib/bundled-plugin-paths.mjs";
 
 export const matrixExtensionIds = ["matrix"];
diff --git a/test/vitest/vitest.extension-mattermost-paths.mjs b/test/vitest/vitest.extension-mattermost-paths.mjs
index 0eb602207f59..8e1cd50d4e19 100644
--- a/test/vitest/vitest.extension-mattermost-paths.mjs
+++ b/test/vitest/vitest.extension-mattermost-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for Mattermost extension tests.
 import { bundledPluginRoot } from "../../scripts/lib/bundled-plugin-paths.mjs";
 
 export const mattermostExtensionIds = ["mattermost"];
diff --git a/test/vitest/vitest.extension-media-paths.mjs b/test/vitest/vitest.extension-media-paths.mjs
index a80551970288..353dc09b12ed 100644
--- a/test/vitest/vitest.extension-media-paths.mjs
+++ b/test/vitest/vitest.extension-media-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for media generation, media understanding, and voice plugins.
 export const mediaExtensionTestRoots = [
   "extensions/alibaba",
   "extensions/deepgram",
diff --git a/test/vitest/vitest.extension-memory-paths.mjs b/test/vitest/vitest.extension-memory-paths.mjs
index 8ff812edf7c7..694a85d83a83 100644
--- a/test/vitest/vitest.extension-memory-paths.mjs
+++ b/test/vitest/vitest.extension-memory-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for memory extension suites.
 export const memoryExtensionTestRoots = [
   "extensions/memory-core",
   "extensions/memory-lancedb",
diff --git a/test/vitest/vitest.extension-messaging-paths.mjs b/test/vitest/vitest.extension-messaging-paths.mjs
index ffd11df71227..27c2fd0271d7 100644
--- a/test/vitest/vitest.extension-messaging-paths.mjs
+++ b/test/vitest/vitest.extension-messaging-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for miscellaneous messaging extension suites.
 import { bundledPluginRoot } from "../../scripts/lib/bundled-plugin-paths.mjs";
 
 export const messagingExtensionIds = [
diff --git a/test/vitest/vitest.extension-misc-paths.mjs b/test/vitest/vitest.extension-misc-paths.mjs
index bc40edbd3446..01a14177104e 100644
--- a/test/vitest/vitest.extension-misc-paths.mjs
+++ b/test/vitest/vitest.extension-misc-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for miscellaneous provider/tool extension suites.
 export const miscExtensionTestRoots = [
   "extensions/arcee",
   "extensions/brave",
diff --git a/test/vitest/vitest.extension-msteams-paths.mjs b/test/vitest/vitest.extension-msteams-paths.mjs
index 6da3d0497527..873855963d64 100644
--- a/test/vitest/vitest.extension-msteams-paths.mjs
+++ b/test/vitest/vitest.extension-msteams-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for Microsoft Teams extension tests.
 import { bundledPluginRoot } from "../../scripts/lib/bundled-plugin-paths.mjs";
 
 export const msTeamsExtensionIds = ["msteams"];
diff --git a/test/vitest/vitest.extension-provider-paths.mjs b/test/vitest/vitest.extension-provider-paths.mjs
index b06cccb8767a..d2f25f7274ad 100644
--- a/test/vitest/vitest.extension-provider-paths.mjs
+++ b/test/vitest/vitest.extension-provider-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for model provider extension suites.
 import { bundledPluginRoot } from "../../scripts/lib/bundled-plugin-paths.mjs";
 
 export const providerExtensionIds = [
diff --git a/test/vitest/vitest.extension-qa-paths.mjs b/test/vitest/vitest.extension-qa-paths.mjs
index dc8bd273b862..904d11fdd68a 100644
--- a/test/vitest/vitest.extension-qa-paths.mjs
+++ b/test/vitest/vitest.extension-qa-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for QA channel/lab extension tests.
 export const qaExtensionTestRoots = ["extensions/qa-channel", "extensions/qa-lab"];
 
 export function isQaExtensionRoot(root) {
diff --git a/test/vitest/vitest.extension-telegram-paths.mjs b/test/vitest/vitest.extension-telegram-paths.mjs
index 2ee49f94d444..3209129d861f 100644
--- a/test/vitest/vitest.extension-telegram-paths.mjs
+++ b/test/vitest/vitest.extension-telegram-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for Telegram extension tests.
 export const telegramExtensionTestRoots = ["extensions/telegram"];
 
 export function isTelegramExtensionRoot(root) {
diff --git a/test/vitest/vitest.extension-voice-call-paths.mjs b/test/vitest/vitest.extension-voice-call-paths.mjs
index 43380f1ddc2c..28f70a26da8a 100644
--- a/test/vitest/vitest.extension-voice-call-paths.mjs
+++ b/test/vitest/vitest.extension-voice-call-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for voice-call extension tests.
 import { bundledPluginRoot } from "../../scripts/lib/bundled-plugin-paths.mjs";
 
 export const voiceCallExtensionIds = ["voice-call"];
diff --git a/test/vitest/vitest.extension-whatsapp-paths.mjs b/test/vitest/vitest.extension-whatsapp-paths.mjs
index c0b8781b31a8..abfded413a52 100644
--- a/test/vitest/vitest.extension-whatsapp-paths.mjs
+++ b/test/vitest/vitest.extension-whatsapp-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for WhatsApp extension tests.
 import { bundledPluginRoot } from "../../scripts/lib/bundled-plugin-paths.mjs";
 
 export const whatsAppExtensionIds = ["whatsapp"];
diff --git a/test/vitest/vitest.extension-zalo-paths.mjs b/test/vitest/vitest.extension-zalo-paths.mjs
index 1a0893567e58..86174efeaa2d 100644
--- a/test/vitest/vitest.extension-zalo-paths.mjs
+++ b/test/vitest/vitest.extension-zalo-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing roots for Zalo extension tests.
 export const zaloExtensionTestRoots = ["extensions/zalo", "extensions/zalouser"];
 
 export function isZaloExtensionRoot(root) {
diff --git a/test/vitest/vitest.plugin-sdk-paths.mjs b/test/vitest/vitest.plugin-sdk-paths.mjs
index ce0bdb2e1732..3ad4ab55d3e6 100644
--- a/test/vitest/vitest.plugin-sdk-paths.mjs
+++ b/test/vitest/vitest.plugin-sdk-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing map for lightweight plugin SDK tests and source triggers.
 const normalizeRepoPath = (value) => value.replaceAll("\\", "/");
 
 const pluginSdkLightEntries = [
diff --git a/test/vitest/vitest.test-shards.mjs b/test/vitest/vitest.test-shards.mjs
index d3a5067f144d..99a77d1a2b8d 100644
--- a/test/vitest/vitest.test-shards.mjs
+++ b/test/vitest/vitest.test-shards.mjs
@@ -1,3 +1,4 @@
+// Full-suite Vitest shard definitions used by test-projects and CI planning.
 export const autoReplyCoreTestInclude = ["src/auto-reply/*.test.ts"];
 
 export const autoReplyCoreTestExclude = ["src/auto-reply/reply*.test.ts"];
diff --git a/test/vitest/vitest.ui-paths.mjs b/test/vitest/vitest.ui-paths.mjs
index 5166ca5d9da3..9e9f25309226 100644
--- a/test/vitest/vitest.ui-paths.mjs
+++ b/test/vitest/vitest.ui-paths.mjs
@@ -1,3 +1,4 @@
+// Test routing globs and predicates for UI unit tests.
 export const unitUiIncludePatterns = [
   "ui/src/ui/app-chat.test.ts",
   "ui/src/ui/chat/**/*.test.ts",
diff --git a/test/vitest/vitest.unit-fast-paths.mjs b/test/vitest/vitest.unit-fast-paths.mjs
index 92dcf3b81da1..992f1e3d2f9c 100644
--- a/test/vitest/vitest.unit-fast-paths.mjs
+++ b/test/vitest/vitest.unit-fast-paths.mjs
@@ -1,3 +1,4 @@
+// Unit-fast test discovery and classification helpers for fast local routing.
 import { spawnSync } from "node:child_process";
 import fs from "node:fs";
 import path from "node:path";
diff --git a/test/vitest/vitest.unit-paths.mjs b/test/vitest/vitest.unit-paths.mjs
index 2287afee3d7d..4ebb7f562e9a 100644
--- a/test/vitest/vitest.unit-paths.mjs
+++ b/test/vitest/vitest.unit-paths.mjs
@@ -1,3 +1,4 @@
+// Unit test routing globs and boundary/bundled-plugin exclusions.
 import path from "node:path";
 import { BUNDLED_PLUGIN_ROOT_DIR } from "../../scripts/lib/bundled-plugin-paths.mjs";