diff --git a/packages/angular/cli/commands/generate-impl.ts b/packages/angular/cli/commands/generate-impl.ts
index 49d9f60056..b47808a7e1 100644
--- a/packages/angular/cli/commands/generate-impl.ts
+++ b/packages/angular/cli/commands/generate-impl.ts
@@ -36,7 +36,6 @@ export class GenerateCommand extends SchematicCommand<GenerateCommandSchema> {
           schematic.description.path,
           this._workflow.registry,
           schematic.description.schemaJson,
-          this.logger,
         );
       } else {
         continue;
diff --git a/packages/angular/cli/models/command-runner.ts b/packages/angular/cli/models/command-runner.ts
index 4828b4239e..28a3c371f3 100644
--- a/packages/angular/cli/models/command-runner.ts
+++ b/packages/angular/cli/models/command-runner.ts
@@ -92,7 +92,7 @@ export async function runCommand(
     }
 
     commandMap[name] =
-      await parseJsonSchemaToCommandDescription(name, schemaPath, registry, schema, logger);
+      await parseJsonSchemaToCommandDescription(name, schemaPath, registry, schema);
   }
 
   let commandName: string | undefined = undefined;
diff --git a/packages/angular/cli/utilities/json-schema.ts b/packages/angular/cli/utilities/json-schema.ts
index 40714c9065..a857867490 100644
--- a/packages/angular/cli/utilities/json-schema.ts
+++ b/packages/angular/cli/utilities/json-schema.ts
@@ -5,7 +5,7 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
-import { json, logging } from '@angular-devkit/core';
+import { BaseException, json } from '@angular-devkit/core';
 import { ExportStringRef } from '@angular-devkit/schematics/tools';
 import { readFileSync } from 'fs';
 import { dirname, resolve } from 'path';
@@ -19,6 +19,13 @@ import {
   Value,
 } from '../models/interface';
 
+
+export class CommandJsonPathException extends BaseException {
+  constructor(public readonly path: string, public readonly name: string) {
+    super(`File ${path} was not found while constructing the subcommand ${name}.`);
+  }
+}
+
 function _getEnumFromValue<E, T extends E[keyof E]>(
   value: json.JsonValue,
   enumeration: E,
@@ -40,7 +47,6 @@ export async function parseJsonSchemaToSubCommandDescription(
   jsonPath: string,
   registry: json.schema.SchemaRegistry,
   schema: json.JsonObject,
-  logger: logging.Logger,
 ): Promise<SubCommandDescription> {
   const options = await parseJsonSchemaToOptions(registry, schema);
 
@@ -69,7 +75,7 @@ export async function parseJsonSchemaToSubCommandDescription(
     try {
       longDescription = readFileSync(ldPath, 'utf-8');
     } catch (e) {
-      logger.warn(`File ${ldPath} was not found while constructing the subcommand ${name}.`);
+      throw new CommandJsonPathException(ldPath, name);
     }
   }
   let usageNotes = '';
@@ -78,7 +84,7 @@ export async function parseJsonSchemaToSubCommandDescription(
     try {
       usageNotes = readFileSync(unPath, 'utf-8');
     } catch (e) {
-      logger.warn(`File ${unPath} was not found while constructing the subcommand ${name}.`);
+      throw new CommandJsonPathException(unPath, name);
     }
   }
 
@@ -99,10 +105,9 @@ export async function parseJsonSchemaToCommandDescription(
   jsonPath: string,
   registry: json.schema.SchemaRegistry,
   schema: json.JsonObject,
-  logger: logging.Logger,
 ): Promise<CommandDescription> {
   const subcommand =
-    await parseJsonSchemaToSubCommandDescription(name, jsonPath, registry, schema, logger);
+    await parseJsonSchemaToSubCommandDescription(name, jsonPath, registry, schema);
 
   // Before doing any work, let's validate the implementation.
   if (typeof schema.$impl != 'string') {
diff --git a/packages/angular/cli/utilities/json-schema_spec.ts b/packages/angular/cli/utilities/json-schema_spec.ts
new file mode 100644
index 0000000000..c26601227c
--- /dev/null
+++ b/packages/angular/cli/utilities/json-schema_spec.ts
@@ -0,0 +1,76 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ *
+ */
+import { schema } from '@angular-devkit/core';
+import { readFileSync } from 'fs';
+import { join } from 'path';
+import { of } from 'rxjs';
+import { CommandJsonPathException, parseJsonSchemaToCommandDescription } from './json-schema';
+
+describe('parseJsonSchemaToCommandDescription', () => {
+  let registry: schema.CoreSchemaRegistry;
+  const baseSchemaJson = {
+    '$schema': 'http://json-schema.org/schema',
+    '$id': 'ng-cli://commands/version.json',
+    'description': 'Outputs Angular CLI version.',
+    '$longDescription': 'not a file ref',
+
+    '$aliases': ['v'],
+    '$scope': 'all',
+    '$impl': './version-impl#VersionCommand',
+
+    'type': 'object',
+    'allOf': [
+      { '$ref': './definitions.json#/definitions/base' },
+    ],
+  };
+
+  beforeEach(() => {
+    registry = new schema.CoreSchemaRegistry([]);
+    registry.registerUriHandler((uri: string) => {
+      if (uri.startsWith('ng-cli://')) {
+        const content = readFileSync(
+          join(__dirname, '..', uri.substr('ng-cli://'.length)), 'utf-8');
+
+        return of(JSON.parse(content));
+      } else {
+        return null;
+      }
+    });
+  });
+
+  it(`should throw on invalid $longDescription path`, async () => {
+    const name = 'version';
+    const schemaPath = join(__dirname, './bad-sample.json');
+    const schemaJson = { ...baseSchemaJson, $longDescription: 'not a file ref' };
+    try {
+      await parseJsonSchemaToCommandDescription(name, schemaPath, registry, schemaJson);
+    } catch (error) {
+      const refPath = join(__dirname, schemaJson.$longDescription);
+      expect(error).toEqual(new CommandJsonPathException(refPath, name));
+
+      return;
+    }
+    expect(true).toBe(false, 'function should have thrown');
+  });
+
+  it(`should throw on invalid $usageNotes path`, async () => {
+    const name = 'version';
+    const schemaPath = join(__dirname, './bad-sample.json');
+    const schemaJson = { ...baseSchemaJson, $usageNotes: 'not a file ref' };
+    try {
+      await parseJsonSchemaToCommandDescription(name, schemaPath, registry, schemaJson);
+    } catch (error) {
+      const refPath = join(__dirname, schemaJson.$usageNotes);
+      expect(error).toEqual(new CommandJsonPathException(refPath, name));
+
+      return;
+    }
+    expect(true).toBe(false, 'function should have thrown');
+  });
+});
diff --git a/scripts/snapshots.ts b/scripts/snapshots.ts
index 318af975a8..83fb0c7bc2 100644
--- a/scripts/snapshots.ts
+++ b/scripts/snapshots.ts
@@ -184,9 +184,9 @@ export default async function(opts: SnapshotsOptions, logger: logging.Logger) {
     const options = { cwd: newProjectRoot };
     const childLogger = logger.createChild(commandName);
     const stdout = _exec(ngPath, [commandName, '--help=json'], options, childLogger);
-    if (stdout.trim()) {
-      fs.writeFileSync(path.join(helpOutputRoot, commandName + '.json'), stdout);
-    }
+    // Make sure the output is JSON before printing it, and format it as well.
+    const jsonOutput = JSON.stringify(JSON.parse(stdout.trim()), undefined, 2);
+    fs.writeFileSync(path.join(helpOutputRoot, commandName + '.json'), jsonOutput);
   }
 
   if (!githubToken) {