I was trying to read a text file into a sensor with
- platform: command_line
name: custom_ls
command: "ls"
scan_interval: 60
This would not create the sensor because the return value was > 255 characters. Allowing sensors and input_textbox fields to have strings larger than 255 characters would permit one to populate a markdown field in lovelace. If a long string field existed, and you could overload objects that used a regular “short” string with this type would allow people to design a richer UI experience.