ShipScript has been an eBay Community volunteer since 2003, specializing in HTML, CSS, Scripts, Photos, Active Content, Technical Solutions, and online Seller Tools.
During the listing process, or after posting the listing, there is no automated method to add the Title or Seller Notes (Condition description) to the item Description.
In the distant past, it was possible to use scripts in the description to pull in other page elements, but scripts have been banned since 2017.
I see that you have a boilerplate as the description and that is why you want to add more info. Without more information, eBay will often extract some of your boilerplate at random to show to phone shoppers as the item description. However, even if you add the title to the description, eBay seems to pass on anything that duplicates the actual title and will pick out some random text.
I see in your HTML that the code set aside as the mobile summary is not functional:
<div typeof="Product" vocab="https://schema.org/">
<p>Thank you for choosing Sport Cards City, the sports cards superstore. We offer a large selection of singles across all sports. Visit our eBay store to view all our items available.<br>
Please review all provided images as we have tried to provide detailed pictures and high detail scans from the cards you will receive. Our opinion of a cards grade may be different from yours. With this said, please feel free to ask any questions you may have about the item. </p>
</div>It has <p> and </p> inside the block, which will cause eBay to ignore it. It is also missing the <span> tags. The code should look like this:
<div vocab="https://schema.org/" typeof="Product">
<span property="description">
...mobile summary without HTML tags...
</span>
</div>
You could replace your code with this:
<div vocab="https://schema.org/" typeof="Product">
<span property="description">
Thank you for choosing Sport Cards City, the sports cards superstore. We offer a large selection of singles across all sports. Visit our eBay store to view all our items available.<br>
Please review all provided images as we have tried to provide detailed pictures and high detail scans from the cards you will receive. Our opinion of a cards grade may be different from yours. With this said, please feel free to ask any questions you may have about the item.
</span>
</div>
To manually add your title and notes to your description, you could set up the HTML tags in your boilerplate and type a placeholder word in your template to make it easier to paste the title and seller notes into your description. For instance, I took this chunk of code from the top of your template and added the placeholder words where they belong. Notice that I put a space around the placeholders. That makes it easier to highlight the word and paste your new text without catching the surrounding tags.
<div class="col-12 col-md-12" style="">
<h1 style="text-align: center; line-height: 45px !important;"><font color="#353535" face="Arial"> {{Title}} </font></h1>
<p style="color: rgb(53, 53, 53); font-family: Arial; font-size: 14pt;"> {{Seller Notes}} </p>
<p style="color: rgb(53, 53, 53); font-family: Arial; font-size: 14pt;"><font face="Arial" style="color: #353535"><img alt="" class="mx-auto d-block img-fluid" src="https://i.postimg.cc/N08p6Ryj/My-project.png"></font></p>
</div>
Another alternative is to use a spreadsheet to create new listings and then use some spreadsheet instructions to concatenate the description from the other cells in the row. However, when using a spreadsheet, you would need to host your images online to supply URLs to the spreadsheet, or, you would need to revise the listings afterwards to manually add photos.
eBay's Seller Hub has a "Reports" tab with an "Uploads" option. A spreadsheet template for your category can be downloaded on the Uploads page and the completed spreadsheet can be uploaded on the same page.
