MySQL 9.4 Release Notes
        
ALTER LIBRARY library_name
    COMMENT "comment_text"
      This statement adds a comment to the named JavaScript library, or
      replaces the existing comment if there is one. Following execution
      of this statement, the updated comment can be viewed in the output
      of SHOW CREATE LIBRARY and in the
      ROUTINE_COMMENT column of the Information
      Schema LIBRARIES table. The comment
      text must be quoted.
    
      To remove a comment from a library without replacing it, specify
      an empty comment string (COMMENT "" or
      COMMENT '').