Drupal Core Update: Mandatory Values for Node Type Fields
The recent update in Drupal Core version 10.3.0, as detailed by Adam G H, brings a significant change regarding the 'help' and 'description' fields within node types. Previously, these fields could contain empty strings by default, but this will no longer be permitted.
The alteration, implemented in #3379091, makes NodeType config entities fully validatable, and enforces that these fields cannot be empty strings to comply with the config schema, as empty strings are deemed nonsensical for this purpose. If empty values are required, they must be explicitly defined as NULL. It's worth noting that despite this change, functions such as \Drupal\node\Entity\NodeType::getDescription() and \Drupal\node\Entity\NodeType::getHelp() will continue to return empty strings for backward compatibility if the fields are set to NULL. This adjustment can have impacts on module developers, themers, and distribution developers as they adapt to this new guideline.
Gather more information here.

