json_schema: {
    "properties": {
      "shape": {
        "description": "The shape for which to calculate the area",
        "enum": [
          "square",
          "rectangle",
          "circle"
        ],
        "type": "string"
      },
      "side_length": {
        "description": "The side length of the square or rectangle, or the radius of the circle",
        "type": "number"
      },
      "width": {
        "description": "The width of the rectangle (only applicable if shape is 'rectangle')",
        "type": "number"
      }
    },
    "required": [
      "shape",
      "side_length"
    ],
    "type": "object"
  }