You can use _rowCount before _results to output the number of records that will be returned.

Ex.

query cmdb_ci($pageSize: Int! = 100, $offset: Int! = 0, $queryConditions: String! = "") {
  GlideRecord_Query {
    cmdb_ci(pagination: {limit: $pageSize, offset: $offset}, queryConditions: $queryConditions) {
      _rowCount _results {
        sys_id {
          value
        }
      }
    }
  }
}