Clarified minor-only option description

src/Composer/Command/ShowCommand.php

@@ -71,7 +71,7 @@ class ShowCommand extends BaseCommand
                 new InputOption('tree', 't', InputOption::VALUE_NONE, 'List the dependencies as a tree'),
                 new InputOption('latest', 'l', InputOption::VALUE_NONE, 'Show the latest version'),
                 new InputOption('outdated', 'o', InputOption::VALUE_NONE, 'Show the latest version but only for packages that are outdated'),
-                new InputOption('minor-only', 'm', InputOption::VALUE_NONE, 'Show the latest version but only for packages that have minor SemVer-compatible updates'),
+                new InputOption('minor-only', 'm', InputOption::VALUE_NONE, 'Show only packages that have minor SemVer-compatible updates. Use with the --outdated option.'),
                 new InputOption('direct', 'D', InputOption::VALUE_NONE, 'Shows only packages that are directly required by the root package'),
             ))
             ->setHelp(<<<EOT