Spain Open Data MCP

Catastro: property details

catastro_property_details

Read-onlyIdempotent

Retrieve use, built area, year built, and units for a Spanish property from its cadastral reference. For 14-character parcel references, get candidates then query one to view its details.

Instructions

Use, built area, year built and units of a property. A 14-char parcel reference with several properties returns candidates; call again with one of them.

Input Schema

Name	Required	Description	Default
`cadastral_reference`	Yes	14 or 20 character cadastral reference

Output Schema

Name	Required	Description
`use`	No
`kind`	No	'UR' urban or 'RU' rural
`units`	No
`address`	No
`candidates`	No	When the parcel holds several properties, their 20-char references
`year_built`	No
`built_area_m2`	No
`cadastral_reference`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 17, 2026

TDQS

A3.8/5.0

Behavior3/5

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

Annotations already declare readOnlyHint and idempotentHint, so further safety disclosure isn't required. The description adds the candidate/ambiguation behavior, which is valuable, but is silent on return format, provenance, or failure modes beyond the candidates case.

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 compact sentences that front-load the requested fields and then state the multi-property behavior; no filler.

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?

For a read-only lookup with a documented parameter and output schema, the description covers purpose and the only surprising behavior (candidate fan-out). It could be more complete if it mentioned what the return object contains or whether the 20-char form bypasses candidates.

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 coverage is 100%, so the schema already documents the single parameter. The description adds only that a 14-char reference can return `candidates` and a retry is needed; this supplements but does not replace schema semantics.

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 resource (property) and the exact attributes returned (use, built area, year built, units). Names the sibling function it is not, and its input domain (parcel reference) is clear.

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

Usage Guidelines3/5

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

The description implies usage via the candidates note; it explains what happens when a 14-char reference matches several properties and directs a follow-up call. However, it does not say when NOT to use it or name alternatives like catastro_coordinates_from_reference.

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

Deploy Server