Summary
Mercado Livre publications, with the exception of those of the fashion category, do not have attribute integration and are hence not catalogued in an illustrative way as required by Mercado Livre, in order to facilitate the end user's viewing.
Since the attribute integration is not available, the attributes should be included in the simple text content of the description. This solution is, however, not recommended by Mercado Livre as the best one for searching and viewing.
Simulation
Unable to reproduce since the Mercado Livre configuration on VTEX Bridge does not give the possibility to upload information about category attributes, except for those belonging to the fashion category.
Workaround
You can perform this integration outside of VTEX Bridge by using Mercado Livre's attribute APIs, available on https://developers.mercadolibre.com/
You may also manually load the attributes to Mercado Livre.