diff --git a/swh/scanner/cli.py b/swh/scanner/cli.py
index c47a394..4ba5a7a 100644
--- a/swh/scanner/cli.py
+++ b/swh/scanner/cli.py
@@ -1,197 +1,199 @@
 # Copyright (C) 2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 # WARNING: do not import unnecessary things here to keep cli startup time under
 # control
 import os
 import sys
 from typing import Any, Dict, Optional
 
 import click
 import yaml
 
 from swh.core import config
 from swh.core.cli import CONTEXT_SETTINGS
 from swh.core.cli import swh as swh_cli_group
 
 from .exceptions import DBError
 
 # All generic config code should reside in swh.core.config
 CONFIG_ENVVAR = "SWH_CONFIG_FILE"
 DEFAULT_CONFIG_PATH = os.path.join(click.get_app_dir("swh"), "global.yml")
 
 DEFAULT_CONFIG: Dict[str, Any] = {
     "web-api": {
         "url": "https://archive.softwareheritage.org/api/1/",
         "auth-token": None,
     }
 }
 
 
 CONFIG_FILE_HELP = f"""Configuration file:
 
 \b
 The CLI option or the environment variable will fail if invalid.
 CLI option is checked first.
 Then, environment variable {CONFIG_ENVVAR} is checked.
 Then, if cannot load the default path, a set of default values are used.
 Default config path is {DEFAULT_CONFIG_PATH}.
 Default config values are:
 
 \b
 {yaml.dump(DEFAULT_CONFIG)}"""
 SCANNER_HELP = f"""Software Heritage Scanner tools.
 
 {CONFIG_FILE_HELP}"""
 
 
 def setup_config(ctx, api_url):
     config = ctx.obj["config"]
     if api_url:
         if not api_url.endswith("/"):
             api_url += "/"
         config["web-api"]["url"] = api_url
 
     return config
 
 
 @swh_cli_group.group(
     name="scanner", context_settings=CONTEXT_SETTINGS, help=SCANNER_HELP,
 )
 @click.option(
     "-C",
     "--config-file",
     default=None,
     type=click.Path(exists=False, dir_okay=False, path_type=str),
     help="""YAML configuration file""",
 )
 @click.pass_context
 def scanner(ctx, config_file: Optional[str]):
 
     env_config_path = os.environ.get(CONFIG_ENVVAR)
 
     # read_raw_config do not fail if file does not exist, so check it beforehand
     # while enforcing loading priority
     if config_file:
         if not config.config_exists(config_file):
             raise click.BadParameter(
                 f"File '{config_file}' cannot be opened.", param_hint="--config-file"
             )
     elif env_config_path:
         if not config.config_exists(env_config_path):
             raise click.BadParameter(
                 f"File '{env_config_path}' cannot be opened.", param_hint=CONFIG_ENVVAR
             )
         config_file = env_config_path
     elif config.config_exists(DEFAULT_CONFIG_PATH):
         config_file = DEFAULT_CONFIG_PATH
 
     conf = DEFAULT_CONFIG
     if config_file is not None:
         conf = config.read_raw_config(config.config_basepath(config_file))
         conf = config.merge_configs(DEFAULT_CONFIG, conf)
 
     ctx.ensure_object(dict)
     ctx.obj["config"] = conf
 
 
 @scanner.command(name="scan")
 @click.argument("root_path", required=True, type=click.Path(exists=True))
 @click.option(
     "-u",
     "--api-url",
     default=None,
     metavar="API_URL",
     show_default=True,
     help="URL for the api request",
 )
 @click.option(
     "--exclude",
     "-x",
     "patterns",
     metavar="PATTERN",
     multiple=True,
     help="Exclude directories using glob patterns \
     (e.g., '*.git' to exclude all .git directories)",
 )
 @click.option(
     "-f",
     "--output-format",
     "out_fmt",
     default="text",
     show_default=True,
     type=click.Choice(["text", "json", "ndjson", "sunburst"], case_sensitive=False),
     help="The output format",
 )
 @click.option(
     "-i", "--interactive", is_flag=True, help="Show the result in a dashboard"
 )
 @click.pass_context
 def scan(ctx, root_path, api_url, patterns, out_fmt, interactive):
     """Scan a source code project to discover files and directories already
     present in the archive"""
     import swh.scanner.scanner as scanner
 
     config = setup_config(ctx, api_url)
     scanner.scan(config, root_path, patterns, out_fmt, interactive)
 
 
 @scanner.group("db")
 @click.pass_context
 def db(ctx):
     pass
 
 
 @db.command("import")
-@click.option(
-    "-s",
-    "--chunk-size",
-    "chunk_size",
-    default="10000",
-    metavar="SIZE",
-    show_default=True,
-    type=int,
-    help="The chunk size ",
-)
 @click.option(
     "-i",
     "--input",
     "input_file",
     metavar="INPUT_FILE",
+    required=True,
     type=click.File("r"),
     help="A file containing SWHIDs",
 )
 @click.option(
     "-o",
     "--output",
     "output_file_db",
     metavar="OUTPUT_DB_FILE",
-    default="SWHID_DB.sqlite",
+    required=True,
     show_default=True,
     help="The name of the generated sqlite database",
 )
+@click.option(
+    "-s",
+    "--chunk-size",
+    "chunk_size",
+    default="10000",
+    metavar="SIZE",
+    show_default=True,
+    type=int,
+    help="The chunk size ",
+)
 @click.pass_context
 def import_(ctx, chunk_size, input_file, output_file_db):
-    """Parse an input list of SWHID to generate a local sqlite database
+    """Create SQLite database of known SWHIDs from a textual list of SWHIDs
+
     """
     from .db import Db
 
     db = Db(output_file_db)
     cur = db.conn.cursor()
     try:
         db.create_from(input_file, chunk_size, cur)
         db.close()
     except DBError:
         print("Failed to create database")
         os.remove(output_file_db)
         sys.exit(1)
 
 
 def main():
     return scanner(auto_envvar_prefix="SWH_SCANNER")
 
 
 if __name__ == "__main__":
     main()