Tag settings
From MoodleDocs
Site administration settings
Enable tags functionality
By default, site-wide tags functionality is enabled. If this is not required, tags functionality may be disabled by an administrator by un-checking the usetags box in Site administration > Advanced features.
Tag capabilities
The following capabilities are related to tags:
Note: The above capabilities may only be applied in the system context except for moodle/course:tag.
There is no capability to create tags since tags are created automatically when users tag content. However only users with the capability 'moodle/tag:manage' can create standard tags. Only standard tags are suggested when users tag any content.