Spain Open Data MCP

Population and households

demographics

Read-onlyIdempotent

Retrieve population, age, sex, household and 5-year trend data for Spanish municipalities, districts or census tracts; compare sub-areas to find where young families or older residents concentrate.

Instructions

Population, sex, five-year age bands, 5-year trend, and household profile for a place in Spain.

Municipality, province and CCAA: census population by age band (latest 1 January),
cross-checked against the official Padrón figure. District and tract: census age bands
and sex from INE's file by census tract. Municipality, district and tract:
household size, single-person households, mean age, share under 18 and 65+ from INE's
income atlas. Use sub_areas to compare a city's districts or tracts, e.g. to find
where young families or older residents concentrate.

Input Schema

Name	Required	Description	Default
`place`	Yes	Place name or INE code: municipality ('Valladolid' or '47186'), province ('41'; a bare name like 'Sevilla' means the city), autonomous community ('Cataluña' or 'CA09'), district ('4718603') or census tract ('4718603012'). 'Name, Province' picks between same-named towns.
`sub_areas`	No	For a municipality, also list its 'district's or census 'tract's. Default 'none'.	none

Output Schema

Name	Required	Description
`data`	Yes
`checks`	No
`sources`	Yes
`confidence`	Yes	Lowest confidence across inputs: high, medium or low. Never state a conclusion more strongly than this.

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv0.1.1Oct 17, 2026

addedOutput schema / $defs / Place / properties / official_name

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "description": "INE's form of the name when it differs ('Palmas de Gran Canaria, Las').",
+  "title": "Official Name"
+}

First observedv0.1.0Oct 16, 2026

TDQS

A4.1/5.0

Behavior4/5

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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuine context beyond that: which official source backs each geography level (census/Padrón vs INE census-tract file vs income atlas) and that figures are latest-1-January and cross-checked, which tells an agent what the numbers actually represent.

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

Conciseness4/5

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

Front-loaded with the core deliverable in the first sentence, then organized as a geography-to-dataset mapping, which is easy to scan. It is slightly repetitive in re-listing the same geography triples, but every clause carries substantive information.

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 an output schema present, return-value documentation is unnecessary, and the description covers the remaining concerns: data provenance, per-geography coverage, the required place identifier, and the optional sub-area expansion. Only an explicit sibling-comparison rule (demographics vs income/market_size) is missing.

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

Parameters4/5

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

Schema coverage is 100%, so the baseline is 3. The description earns a notch above that by tying data availability to the geography argument: municipality/province/CCAA yield census plus Padrón, district/tract yield census age bands and sex, and household metrics exist only at municipality/district/tract — context the schema does not state.

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?

Names the exact resource set (population, sex, five-year age bands, trend, household profile) and the exact scope (a place in Spain). The enumerated geography levels and data sources make it unmistakable against siblings such as income, rents, crime, or businesses, which cover entirely different subject matter.

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?

It gives one concrete usage example ('use sub_areas to compare a city's districts or tracts, e.g. to find where young families or older residents concentrate'), which is implied guidance rather than an explicit when-to-use rule. It never states when to prefer demographics over income, market_size, or catchment, nor any exclusions.

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

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