Currently, there's no option to fetch/restrict the response to specific attributes https://developer.atlassian.com/cloud/assets/rest/api-group-object/#api-object-aql-post

It would be nice to have this ability, similar to other endpoints such as https://developer.atlassian.com/cloud/jira/platform/rest/v3/api-group-issue-search/#api-rest-api-3-search-get

On this endpoint, you can define which fields to return via the fields array<string> parameter.