diff --git a/change/change-98c52c45-9c3f-4c30-9fca-4f6e22e36730.json b/change/change-98c52c45-9c3f-4c30-9fca-4f6e22e36730.json
new file mode 100644
index 000000000..573f3d527
--- /dev/null
+++ b/change/change-98c52c45-9c3f-4c30-9fca-4f6e22e36730.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "type": "patch",
+      "comment": "Better validation and docs of reporter names",
+      "packageName": "@lage-run/cli",
+      "email": "elcraig@microsoft.com",
+      "dependentChangeType": "patch"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/packages/cli/package.json b/packages/cli/package.json
index f457f94d6..e62adac10 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -15,8 +15,8 @@
   "main": "lib/index.js",
   "types": "lib/index.d.ts",
   "scripts": {
-    "build": "tsc",
-    "start": "tsc -w --preserveWatchOutput",
+    "build": "yarn run -T tsc",
+    "start": "yarn run -T tsc -w --preserveWatchOutput",
     "test": "monorepo-scripts jest",
     "lint": "monorepo-scripts lint"
   },
diff --git a/packages/cli/src/commands/createReporter.ts b/packages/cli/src/commands/createReporter.ts
index fc005830b..2be60196e 100644
--- a/packages/cli/src/commands/createReporter.ts
+++ b/packages/cli/src/commands/createReporter.ts
@@ -7,7 +7,7 @@ import {
   VerboseFileLogReporter,
   ChromeTraceEventsReporter,
 } from "@lage-run/reporters";
-import type { ReporterInitOptions } from "../types/ReporterInitOptions.js";
+import type { BuiltInReporterName, ReporterInitOptions } from "../types/ReporterInitOptions.js";
 import type { Reporter } from "@lage-run/logger";
 import { findPackageRoot } from "workspace-tools";
 import { readFileSync } from "fs";
@@ -26,7 +26,7 @@ export async function createReporter(
   const packageJson = JSON.parse(readFileSync(path.join(root, "package.json"), "utf-8"));
   const version = packageJson.version;
 
-  switch (reporter) {
+  switch (reporter as BuiltInReporterName) {
     case "profile":
       return new ChromeTraceEventsReporter({
         concurrency,
@@ -45,39 +45,38 @@ export async function createReporter(
     case "verboseFileLog":
     case "vfl":
       return new VerboseFileLogReporter(logFile);
+  }
 
-    default:
-      // Check if it's a custom reporter defined in config
-      if (customReporters && customReporters[reporter]) {
-        const reporterPath = customReporters[reporter];
-        const resolvedPath = path.isAbsolute(reporterPath) ? reporterPath : path.resolve(process.cwd(), reporterPath);
-
-        try {
-          // Use dynamic import to load the custom reporter module
-          // This works with both ESM (.mjs, .js with type: module) and CommonJS (.cjs, .js) files
-          const reporterModule = await import(pathToFileURL(resolvedPath).href);
+  // Check if it's a custom reporter defined in config
+  if (customReporters && customReporters[reporter]) {
+    const reporterPath = customReporters[reporter];
+    const resolvedPath = path.isAbsolute(reporterPath) ? reporterPath : path.resolve(process.cwd(), reporterPath);
 
-          // Try different export patterns
-          const ReporterClass = reporterModule.default ?? reporterModule[reporter] ?? reporterModule;
+    try {
+      // Use dynamic import to load the custom reporter module
+      // This works with both ESM (.mjs, .js with type: module) and CommonJS (.cjs, .js) files
+      const reporterModule = await import(pathToFileURL(resolvedPath).href);
 
-          if (typeof ReporterClass === "function") {
-            return new ReporterClass(options);
-          } else if (typeof ReporterClass === "object" && ReporterClass !== null) {
-            // If it's already an instance
-            return ReporterClass;
-          } else {
-            throw new Error(`Custom reporter "${reporter}" at "${resolvedPath}" does not export a valid reporter class or instance.`);
-          }
-        } catch (error) {
-          throw new Error(`Failed to load custom reporter "${reporter}" from "${resolvedPath}": ${error}`);
-        }
-      }
+      // Try different export patterns
+      const ReporterClass = reporterModule.default ?? reporterModule[reporter] ?? reporterModule;
 
-      // Default reporter behavior
-      if (progress && !(logLevel >= LogLevel.verbose || verbose || grouped)) {
-        return new ProgressReporter({ concurrency, version });
+      if (typeof ReporterClass === "function") {
+        return new ReporterClass(options);
+      } else if (typeof ReporterClass === "object" && ReporterClass !== null) {
+        // If it's already an instance
+        return ReporterClass;
+      } else {
+        throw new Error(`Custom reporter "${reporter}" at "${resolvedPath}" does not export a valid reporter class or instance.`);
       }
+    } catch (error) {
+      throw new Error(`Failed to load custom reporter "${reporter}" from "${resolvedPath}": ${error}`);
+    }
+  }
 
-      return new LogReporter({ grouped, logLevel: verbose ? LogLevel.verbose : logLevel });
+  // Default reporter behavior
+  if (progress && !(logLevel >= LogLevel.verbose || verbose || grouped)) {
+    return new ProgressReporter({ concurrency, version });
   }
+
+  return new LogReporter({ grouped, logLevel: verbose ? LogLevel.verbose : logLevel });
 }
diff --git a/packages/cli/src/commands/initializeReporters.ts b/packages/cli/src/commands/initializeReporters.ts
index e8c0aa924..b5d08e40e 100644
--- a/packages/cli/src/commands/initializeReporters.ts
+++ b/packages/cli/src/commands/initializeReporters.ts
@@ -1,24 +1,41 @@
 import { createReporter } from "./createReporter.js";
 import type { Logger } from "@lage-run/logger";
-import type { ReporterInitOptions } from "../types/ReporterInitOptions.js";
+import {
+  type BuiltInReporterName,
+  type ReporterInitOptions,
+  type ReporterName,
+  builtInReporterNames,
+} from "../types/ReporterInitOptions.js";
 
 export async function initializeReporters(logger: Logger, options: ReporterInitOptions, customReporters: Record<string, string> = {}) {
   const { reporter } = options;
 
+  const supportedReportersLower = Object.fromEntries(
+    [...builtInReporterNames, ...Object.keys(customReporters)].map((name) => [name.toLowerCase(), name])
+  );
+
   // filter out falsy values (e.g. undefined) from the reporter array
-  const reporterOptions = (Array.isArray(reporter) ? reporter : [reporter]).filter(Boolean);
+  const reporterOptions = (Array.isArray(reporter) ? reporter : [reporter]).filter(Boolean) as ReporterName[];
 
   if (reporterOptions.length === 0) {
     // "default" is just a dummy name to trigger the default case in createReporter
-    reporterOptions.push("default");
+    reporterOptions.push("default" satisfies BuiltInReporterName);
   }
 
   // add profile reporter if --profile is passed
   if (options.profile) {
-    reporterOptions.push("profile");
+    reporterOptions.push("profile" satisfies BuiltInReporterName);
   }
 
-  for (const reporterName of reporterOptions) {
+  for (const rawReporterName of reporterOptions) {
+    // Validate the given name, but be flexible about the casing
+    const reporterName = supportedReportersLower[rawReporterName.toLowerCase()];
+    if (!reporterName) {
+      throw new Error(
+        `Invalid --reporter option: "${rawReporterName}". Supported reporters are: ${Object.keys(supportedReportersLower).join(", ")}`
+      );
+    }
+
     const reporterInstance = await createReporter(reporterName, options, customReporters);
     logger.addReporter(reporterInstance);
   }
diff --git a/packages/cli/src/commands/options.ts b/packages/cli/src/commands/options.ts
index 7b0977d48..ffe2450bc 100644
--- a/packages/cli/src/commands/options.ts
+++ b/packages/cli/src/commands/options.ts
@@ -1,10 +1,13 @@
 import { Option } from "commander";
+import { builtInReporterNames } from "../types/ReporterInitOptions.js";
 
 const isCI = process.env.CI || process.env.TF_BUILD;
 
+const reporterChoices = builtInReporterNames.filter((n) => n !== "default" && n !== "profile");
+
 const options = {
   logger: {
-    reporter: new Option("--reporter <reporter...>", "reporter"),
+    reporter: new Option("--reporter <reporter...>", `log reporter (built-in choices: ${reporterChoices.join(", ")})`),
     grouped: new Option("--grouped", "groups the logs").default(false),
     progress: new Option("--progress").conflicts(["reporter", "grouped", "verbose"]).default(!isCI),
     logLevel: new Option("--log-level <level>", "log level").choices(["info", "warn", "error", "verbose", "silly"]).conflicts("verbose"),
diff --git a/packages/cli/src/types/ReporterInitOptions.ts b/packages/cli/src/types/ReporterInitOptions.ts
index ef6b45611..a10ab22e5 100644
--- a/packages/cli/src/types/ReporterInitOptions.ts
+++ b/packages/cli/src/types/ReporterInitOptions.ts
@@ -1,7 +1,25 @@
 import type { LogLevel } from "@lage-run/logger";
 
+/** All the built-in reporter names */
+export type BuiltInReporterName = "default" | "profile" | "json" | "azureDevops" | "adoLog" | "npmLog" | "old" | "verboseFileLog" | "vfl";
+/** Built-in or custom reporter name */
+export type ReporterName = BuiltInReporterName | string;
+
+export const builtInReporterNames = Object.keys({
+  json: true,
+  azureDevops: true,
+  npmLog: true,
+  verboseFileLog: true,
+  vfl: true,
+  adoLog: true,
+  old: true,
+  default: true,
+  profile: true,
+  // This verifies all reporters are listed
+} satisfies Record<BuiltInReporterName, true>);
+
 export interface ReporterInitOptions {
-  reporter: string[] | string;
+  reporter: ReporterName[] | ReporterName | undefined;
   progress: boolean;
   verbose: boolean;
   grouped: boolean;