describe_item

The describe_item tool returns full information about a single ArcGIS Portal item, given its item ID. AI agents typically call it after Search Content has narrowed the candidates down to one—or whenever a user pastes an item ID directly into a prompt and expects a description back.

Tool Name

describe_item

Tool Alias

Describe Item

Objective

Retrieve detailed information about a specific ArcGIS Portal item by its item ID, optionally including the service definition for service items or the item data for non-service items.

Description

describe_item retrieves information about ArcGIS Portal items in the user's portal and organization by their item IDs. The client can optionally request additional details about the item, controlled by the fetchAdditionalDetails parameter.

The fetchAdditionalDetails parameter defaults to true and should generally be left at the default—additional details are usually valuable and inexpensive to fetch.

When fetchAdditionalDetails is true, what gets returned alongside the core item information depends on the item's type:

  • Service items with an ArcGIS Server REST endpoint — For items such as feature services and map services, the response includes the service definition of the item. This is the service-level metadata an agent needs to plan further calls, including the list of layers and tables, spatial reference, and capabilities.
  • Non-service items — For items such as web maps and dashboards, the response includes the item's data JSON from its /data endpoint.
  • Other items — If neither rule applies, no additional details are fetched. The response contains only the core item information.

If the request to fetch additional details succeeds, those details are returned in the additionalDetails field. If the request fails for any reason, the tool still returns the core item information; the additionalDetails field is set to null and the error encountered while fetching is logged. The tool does not fail the whole call.

When to use

  • The client wants the full details of an ArcGIS Portal item.
  • The client does not need the full details of an individual layer inside a service item—describe_item does not fetch per-layer definitions.

When not to use

  • The client needs the full details of an individual layer of a service item—typically as a precursor to running a layer query. Use describe_layer instead.

Tip Calling describe_item first on a service item is a useful precursor to describe_layer: its service definition enumerates the available layers and their IDs, which you can then pass to describe_layer.

Schema

The full JSON Schema definitions for the input parameters accepted by describe_item and the output payload it returns are provided as separate files alongside this document.

Input schema

The input schema describes the required itemId parameter and the optional fetchAdditionalDetails flag.

Download or view DescribePortalItemToolInputSchema.json

Output schema

The output schema describes the response object returned by the tool, including the core itemInfo and—when requested—the additionalDetails block (a service definition for service items, or the item's data JSON for non-service items).

Download or view DescribePortalItemToolOutputSchema.json

Sample prompts to test the tool

Send any of the prompts below to your MCP-compatible AI client to verify that describe_item is working correctly. The prompts are grouped to exercise different aspects of the tool—coverage of various item types, edge cases, multi-item comparisons, metadata-quality questions, owner and lineage queries, and capability checks.

Item-type coverage

  • Can you explain the California feature service?
  • Can you explain the WMS services I have in my ArcGIS Enterprise?
  • Describe the dem image service.
  • Tell me about the Landsat8 image service.
  • Explain the PrintingTools geoprocessing service.
  • Tell me about the Geometry utility service.
  • What is the SampleWorldCities OGCFeatureServer?

Edge cases

  • Describe the Vision Zero Safety service without fetching extra details.
  • Describe item ID 0000000000000000.

Comparison and multi-item

  • Compare the California and SanFrancisco feature services—do they share the same schema?
  • What's the difference between the dem, Landsat8, and cog image services?
  • Are the SampleWorldCities items (Map Service, OGCFeatureServer, and WMS) backed by the same data?

Metadata quality

  • Which of my hosted feature services have a completeness score below 30?
  • Describe New Jersey Preserved Farms—is the metadata publication-ready?
  • What's the access level and sharing status of the DE Development Applications service?

Owner and lineage

  • Show me everything about every item created on the same day as the California feature service.

Capability checks

  • Can the Vision Zero Safety service be edited, or is it query-only?
  • What spatial reference does the DE Development Applications service use?
  • What export formats does New Jersey Preserved Farms support?
  • Does the California feature service have sync enabled?
  • What's the max record count on the SanFrancisco service?