Error when creating new document type in Desk tool

import { PackageIcon } from '@sanity/icons'
import pluralize from 'pluralize'

export default {
  name: 'commonDescription',
  title: 'Common Description',
  type: 'document',
  icon: PackageIcon,
  fields: [
    // Title
    {
      name: 'title',
      title: 'Title',
      type: 'string',
      validation: Rule => Rule.required()
    },
    // Description
    {
      name: 'description',
      title: 'Description',
      type: 'block'
    },
    //Size Chart
    {
        name: 'sizeChart',
        title: 'Size Chart',
        type: 'block'
      },

    
  ],
  preview: {
    select: {
      title: 'title'
    },
    prepare(selection) {
      const { title } = selection
      return {
        title
      }
    }
  }
}

export default {
    name: 'description',
    title: 'Description',
    type: 'array',
    of: [
      {
        lists: [
          { title: 'Bullet', value: 'bullet' },
          { title: 'Numbered', value: 'number' }
        ],
        marks: {
          annotations: [
            // Product
            {
              name: 'annotationProduct',
              type: 'annotationProduct'
            },
            // Email
            {
              name: 'annotationLinkEmail',
              type: 'annotationLinkEmail'
            },
            // Internal link
            {
              name: 'annotationLinkInternal',
              type: 'annotationLinkInternal'
            },
            // URL
            {
              name: 'annotationLinkExternal',
              type: 'annotationLinkExternal'
            }
          ],
          decorators: [
            {
              title: 'Italic',
              value: 'em'
            },
            {
              title: 'Strong',
              value: 'strong'
            }
          ]
        },
        // Inline blocks
        of: [{ type: 'blockInlineProduct' }, { type: 'blockInlineProductMarginalia' }],
        styles: [
          { title: 'Heading', value: 'h2' },
          { title: 'Quote', value: 'blockquote' }
        ],
        type: 'block'
      },
      // Custom blocks
      {
        name: 'blockImage',
        type: 'blockImage'
      },
      {
        name: 'blockProduct',
        type: 'blockProduct'
      }
    ]
  }