diff --git a/tools/src/Logger.ts b/tools/src/Logger.ts
index 3585f1ecb..61a3f7284 100644
--- a/tools/src/Logger.ts
+++ b/tools/src/Logger.ts
@@ -16,10 +16,20 @@ export enum LogLevel {
 export class Logger {
   level: LogLevel
 
-  constructor (level: LogLevel) {
+  static messages = {
+    [LogLevel.error]: 'ERROR',
+    [LogLevel.warn]: 'WARNING',
+    [LogLevel.info]: 'INFO'
+  }
+
+  constructor (level: LogLevel = LogLevel.warn) {
     this.level = level
   }
 
+  log (message: string): void {
+    console.log(message)
+  }
+
   info (message: string): void {
     this.#log(LogLevel.info, message)
   }
@@ -34,9 +44,7 @@ export class Logger {
 
   #log (level: LogLevel, message: string): void {
     if (level > this.level) return
-    const output = `[${level}] ${message}`
-    if (level === LogLevel.error) console.error(output)
-    if (level === LogLevel.warn) console.warn(output)
-    if (level === LogLevel.info) console.info(output)
+    const output = `[${Logger.messages[level]}] ${message}`
+    console.log(output)
   }
 }
diff --git a/tools/src/merger/OpenApiMerger.ts b/tools/src/merger/OpenApiMerger.ts
index 4cded34bb..67af89e56 100644
--- a/tools/src/merger/OpenApiMerger.ts
+++ b/tools/src/merger/OpenApiMerger.ts
@@ -24,8 +24,8 @@ export default class OpenApiMerger {
   paths: Record<string, Record<string, OpenAPIV3.PathItemObject>> = {} // namespace -> path -> path_item_object
   schemas: Record<string, Record<string, OpenAPIV3.SchemaObject>> = {} // category -> schema -> schema_object
 
-  constructor (root_folder: string, log_level: LogLevel = LogLevel.warn) {
-    this.logger = new Logger(log_level)
+  constructor (root_folder: string, logger: Logger = new Logger(LogLevel.warn)) {
+    this.logger = logger
     this.root_folder = fs.realpathSync(root_folder)
     this.spec = {
       openapi: '3.1.0',
@@ -47,6 +47,8 @@ export default class OpenApiMerger {
     this.#generate_global_params()
     this.#generate_superseded_ops()
 
+    this.logger.info(`Writing ${output_path} ...`)
+
     if (output_path !== '') write_yaml(output_path, this.spec)
     return this.spec as OpenAPIV3.Document
   }
@@ -55,6 +57,7 @@ export default class OpenApiMerger {
   #merge_namespaces (): void {
     const folder = `${this.root_folder}/namespaces`
     fs.readdirSync(folder).forEach(file => {
+      this.logger.info(`Merging namespaces in ${folder}/${file} ...`)
       const spec = read_yaml(`${folder}/${file}`)
       this.redirect_refs_in_namespace(spec)
       this.spec.paths = { ...this.spec.paths, ...spec.paths }
@@ -78,6 +81,7 @@ export default class OpenApiMerger {
   #merge_schemas (): void {
     const folder = `${this.root_folder}/schemas`
     fs.readdirSync(folder).forEach(file => {
+      this.logger.info(`Merging schema ${folder}/${file} ...`)
       const spec = read_yaml(`${folder}/${file}`)
       const category = file.split('.yaml')[0]
       this.redirect_refs_in_schema(category, spec)
diff --git a/tools/src/merger/SupersededOpsGenerator.ts b/tools/src/merger/SupersededOpsGenerator.ts
index 7f941c1c3..72f8ee5b6 100644
--- a/tools/src/merger/SupersededOpsGenerator.ts
+++ b/tools/src/merger/SupersededOpsGenerator.ts
@@ -30,7 +30,7 @@ export default class SupersededOpsGenerator {
       const superseded_path = this.copy_params(superseded_by, path)
       const path_entry = _.entries(spec.paths as Document).find(([path, _]) => regex.test(path))
       if (path_entry != null) spec.paths[superseded_path] = this.path_object(path_entry[1], operation_keys)
-      else this.logger.warn(`Warning: ${path} is superseded by a path that does not exist: ${superseded_by}`)
+      else this.logger.warn(`${path} is superseded by a path that does not exist: ${superseded_by}`)
     }
   }
 
diff --git a/tools/src/merger/merge.ts b/tools/src/merger/merge.ts
index 470a274fe..50af3360b 100644
--- a/tools/src/merger/merge.ts
+++ b/tools/src/merger/merge.ts
@@ -10,16 +10,19 @@
 import { Command, Option } from '@commander-js/extra-typings'
 import OpenApiMerger from './OpenApiMerger'
 import { resolve } from 'path'
+import { Logger, LogLevel } from '../Logger'
 
 const command = new Command()
   .description('Merges the multi-file OpenSearch spec into a single file for programmatic use.')
   .addOption(new Option('-s, --source <path>', 'path to the root folder of the multi-file spec').default(resolve(__dirname, '../../../spec')))
   .addOption(new Option('-o, --output <path>', 'output file name').default(resolve(__dirname, '../../../build/opensearch-openapi.yaml')))
+  .addOption(new Option('--verbose', 'show merge details').default(false))
   .allowExcessArguments(false)
   .parse()
 
 const opts = command.opts()
-const merger = new OpenApiMerger(opts.source)
-console.log(`Merging ${opts.source} into ${opts.output} ...`)
+const logger = new Logger(opts.verbose ? LogLevel.info : LogLevel.warn)
+const merger = new OpenApiMerger(opts.source, logger)
+logger.log(`Merging ${opts.source} into ${opts.output} ...`)
 merger.merge(opts.output)
-console.log('Done.')
+logger.log('Done.')
diff --git a/tools/tests/Logger.test.ts b/tools/tests/Logger.test.ts
new file mode 100644
index 000000000..77d9ad0b6
--- /dev/null
+++ b/tools/tests/Logger.test.ts
@@ -0,0 +1,102 @@
+/*
+* Copyright OpenSearch Contributors
+* SPDX-License-Identifier: Apache-2.0
+*
+* The OpenSearch Contributors require contributions made to
+* this file be licensed under the Apache-2.0 license or a
+* compatible open source license.
+*/
+
+import { Logger, LogLevel } from '../src/Logger'
+
+describe('Logger', () => {
+  let log: jest.Mock
+
+  beforeEach(() => {
+    log = console.log = jest.fn()
+  })
+
+  afterEach(() => {
+    log.mockClear()
+  })
+
+  describe('at default log level', () => {
+    const logger = new Logger()
+
+    test('sets log level at warn', () => {
+      expect(logger.level).toEqual(LogLevel.warn)
+    })
+
+    test('does not log info level messages', () => {
+      logger.log('log')
+      logger.error('error')
+      logger.warn('warn')
+      logger.info('info')
+      expect(log.mock.calls).toEqual([
+        ['log'],
+        ['[ERROR] error'],
+        ['[WARNING] warn']
+      ])
+    })
+  })
+
+  describe('at info log level', () => {
+    const logger = new Logger(LogLevel.info)
+
+    test('sets log level at info', () => {
+      expect(logger.level).toEqual(LogLevel.info)
+    })
+
+    test('logs all messages', () => {
+      logger.log('log')
+      logger.error('error')
+      logger.warn('warn')
+      logger.info('info')
+      expect(log.mock.calls).toEqual([
+        ['log'],
+        ['[ERROR] error'],
+        ['[WARNING] warn'],
+        ['[INFO] info']
+      ])
+    })
+  })
+
+  describe('at warn log level', () => {
+    const logger = new Logger(LogLevel.warn)
+
+    test('sets log level at warn', () => {
+      expect(logger.level).toEqual(LogLevel.warn)
+    })
+
+    test('does not log info messages', () => {
+      logger.log('log')
+      logger.error('error')
+      logger.warn('warn')
+      logger.info('info')
+      expect(log.mock.calls).toEqual([
+        ['log'],
+        ['[ERROR] error'],
+        ['[WARNING] warn']
+      ])
+    })
+  })
+
+  describe('at error log level', () => {
+    const logger = new Logger(LogLevel.error)
+
+    test('sets log level at error', () => {
+      expect(logger.level).toEqual(LogLevel.error)
+    })
+
+    test('does not log warn and info messages', () => {
+      logger.log('log')
+      logger.error('error')
+      logger.warn('warn')
+      logger.info('info')
+      expect(log.mock.calls).toEqual([
+        ['log'],
+        ['[ERROR] error']
+      ])
+    })
+  })
+})