Arcana. Although calligraphy is of little help in deciphering the content of magical writings, proficiency with these supplies can aid in identifying who wrote a script of a magical nature.
History. This tool proficiency can augment the benefit of successful checks made to analyze or investigate ancient writings, scrolls, or other texts, including runes etched in stone or messages in frescoes or other displays.
Decipher Treasure Map. This tool proficiency grants you expertise in examining maps. You can make an Intelligence check to determine a map's age, whether a map includes any hidden messages, or similar facts.
Additional uses. You can use your calligrapher's supplies to do a variety of things, as your DM if you may use the tools for a specific task. Examples of such tasks are as follows; Identify writer of nonmagical script, determine writer's state of mind, spot forged text, forge a signature.