Andres,
You can call Portal's REST API to get the details of that item by using the GUID
.../sharing/rest/content/items/<insert map id here>?token=<insert token here>&f=json
{
"id": "<map id>",
"owner": "",
"created": 1505265579683,
"modified": 1517563154747,
"guid": null,
"name": null,
"title": "Network Operations Viewer Map - UAT Testing and NOT for Production use",
"type": "Web Map",
"typeKeywords": [
"ArcGIS Online",
"Explorer Web Map",
"Map",
"Online Map",
"Web Map"
],
"description": "UAT Testing and NOT for Production use",
"tags": [
"ips",
"protection",
"network",
"operation"
],
etc, etc.