@NewbieGirlJen Thank you for your patience as I researched the search capabilities within the APIM developer portal.
At this time, it is not possible to search beyond the name of the APIs within the APIM developer portal.
We would suggest you request this as a feature within the Azure Feedback site here as the product group reviews feedback for ideas on what to add next.
If you have any further questions or concerns, please reply to my post and we can assist you further.