Skip to main content
Glama

Previsualizar los datos de un recurso

preview_resource_data
Read-only

Preview the first rows of an Ecuadorian open-data CKAN resource as a table, supporting CSV, JSON, Excel, ODS, and compressed CSV up to 5 MB before downloading. For DataStore, use query_resource_data.

Instructions

First rows of a CKAN resource as a table: CSV/TSV, JSON/GeoJSON, XLS/XLSX/XLSB, ODS, and ZIP/tar.gz wrapping a CSV. Max 5 MB; for DataStore resources prefer query_resource_data.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
rowsNoNumber of data rows to preview (default: 20, max: 100)
formatNotext summary (default) or json structured result.text
sourceNoCKAN portal; nacional (default), cuenca, latacunga or iadb.nacional
resource_idYesThe resource UUID (get it from list_dataset_resources)

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changedv0.13.0
    • changedOutput schema / (root)
      Previous value: -{
      -  "additionalProperties": true,
      -  "type": "object"
      -}New value: +null
  2. Changed4 schema fields changedv0.10.0
    • addedInput schema / properties / format / description
      Added value: +"text summary (default) or json structured result."
    • addedInput schema / properties / resource_id / description
      Added value: +"The resource UUID (get it from list_dataset_resources)"
    • addedInput schema / properties / rows / description
      Added value: +"Number of data rows to preview (default: 20, max: 100)"
    • addedInput schema / properties / source / description
      Added value: +"CKAN portal; nacional (default), cuenca, latacunga or iadb."
  3. Changed6 schema fields changedv0.8.14
    • removedInput schema / properties / format / title
      Removed value: -"Format"
    • removedInput schema / properties / resource_id / title
      Removed value: -"Resource Id"
    • removedInput schema / properties / rows / title
      Removed value: -"Rows"
    • removedInput schema / properties / source / title
      Removed value: -"Source"
    • removedInput schema / title
      Removed value: -"preview_resource_dataArguments"
    • removedOutput schema / title
      Removed value: -"preview_resource_dataDictOutput"
  4. First observedv0.8.12

TDQS

A4.2/5.0
Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, destructiveHint=false, openWorldHint=true, so safety is covered. The description adds real behavior beyond them: the 5 MB size ceiling, the accepted file formats, and the fact that ZIP/tar.gz archives containing a CSV are unwrapped and previewed.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, zero filler. The capability and format list come first, with the limit and routing hint compressed into the trailing clause.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description still conveys the return shape ('as a table', text vs json via schema). It does not mention pagination, error behavior for oversized files, or which portal index to consult, but the essentials for a correct call are present.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so rows/format/source/resource_id are all documented in the schema (defaults, max 100, enums). The description adds no per-parameter syntax or format detail beyond the 5 MB cap, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (preview) plus resource (CKAN resource) and even the shape of the result ('as a table'). The supported format list and the explicit hand-off to query_resource_data for DataStore resources separate it from siblings like download_resource and query_resource_data.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Names a concrete alternative and the condition selecting it: 'for DataStore resources prefer query_resource_data'. It does not state when to prefer download_resource or list_dataset_resources instead, so the routing guidance is clear but not exhaustive.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server

Other Tools