minecraft-bedrock-json-schemas/source/general/array_3_number.json

{
  "$id": "general.array.number.3",
  "type": "array",
  "title": "Array Of 3 Items",
  "description": "An array of 3 numbers",
  "minimum": 3,
  "maximum": 3,
  "items": { "type": "number", "description": "An number", "title": "TODO Title" }
}