Cenogram - Polish Real Estate Data

get_rental_yield

Read-only

EXPERIMENTAL (beta): this tool may change or be withdrawn without notice; do not build critical workflows on it. Estimate the gross rental yield for a Polish city or county: annualized median asking rent (PLN/m²/month × 12) divided by the median apartment transaction price per m² (secondary market) from the RCN registry. Gross and top-line only — excludes vacancy, management, tax and maintenance. Indicative, not investment advice. Address by location (city name → resolves to a county) OR teryt (4-digit county code; 6-digit = dzielnica where available, today Warszawa's 18 districts, otherwise truncated to the county; teryt wins when both are given). Both sides need at least 5 samples or the result is suppressed. Not comparable across cities with different as_of dates (RCN publication lag varies by county). Rent and transaction prices come from different sources, so the yield is an approximation. Coverage is county-level only (miasta na prawach powiatu) plus Warszawa's 18 districts, and further limited to cities with asking-rent data. A town inside a larger powiat (e.g. Sandomierz, Pruszków), a non-Warszawa city district, or an osiedle does NOT resolve and returns a 404 — do not pass such names. Unless the location is a major city you already know is covered, call list_rental_yield_locations FIRST to get valid names, or pass a 4-digit county TERYT. Optional areaBucket restricts both sides to an apartment area range in m2 (e.g. '40-50'). Area ranges are NOT additive — a bucket does not sum back to 'all'. The transaction-price denominator uses the market median. Note: median/average prices are market-based — fractional ownership shares and non-market deeds (public tenders, foreclosures, privileged/subsidized sales) are excluded from price aggregates. Transaction counts and coverage stay complete.

Input Schema

TableJSON Schema

Name	Required	Description
`teryt`	No	TERYT code. 4 digits = county (e.g. 1465 = Warszawa). 6 digits = dzielnica where available (today: Warszawa's 18 districts, e.g. 146510 = Śródmieście) → yield for that district. Other longer codes (gmina/precinct) are truncated to the county. Wins over location when both are provided.
`location`	No	County-level city name — a miasto na prawach powiatu or a catalog entry from list_rental_yield_locations (e.g. 'Warszawa', 'Kraków', 'Gdańsk'). A Warszawa district name (e.g. 'Mokotów') narrows to that district; another city's delegatura (e.g. 'Kraków-Podgórze') resolves to its parent county. A town within a larger powiat or an osiedle will 404 — check the catalog or use teryt first. Use this OR teryt.
`areaBucket`	No	Apartment area range in m2: all (default, whole stock), 0-30, 30-40, 40-50, 50-60, 60-80, 80+. Bucket values are not additive.

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedSep 20, 2026

changedInput schema / properties / location / description

Previous value: -"County-level city name — must be a miasto na prawach powiatu or a catalog entry from list_rental_yield_locations (e.g. 'Warszawa', 'Kraków', 'Gdańsk'). A town within a larger powiat, a non-Warszawa district, or an osiedle will 404 — check the catalog or use teryt first. Use this OR teryt."New value: +"County-level city name — a miasto na prawach powiatu or a catalog entry from list_rental_yield_locations (e.g. 'Warszawa', 'Kraków', 'Gdańsk'). A Warszawa district name (e.g. 'Mokotów') narrows to that district; another city's delegatura (e.g. 'Kraków-Podgórze') resolves to its parent county. A town within a larger powiat or an osiedle will 404 — check the catalog or use teryt first. Use this OR teryt."

Changed1 schema field changedJul 11, 2026

changedInput schema / properties / location / description

Previous value: -"City name, resolves to a county (e.g. 'Warszawa', 'Kraków', 'Gdańsk'). Use this OR teryt."New value: +"County-level city name — must be a miasto na prawach powiatu or a catalog entry from list_rental_yield_locations (e.g. 'Warszawa', 'Kraków', 'Gdańsk'). A town within a larger powiat, a non-Warszawa district, or an osiedle will 404 — check the catalog or use teryt first. Use this OR teryt."

Changed1 schema field changedJul 8, 2026

changedInput schema / properties / teryt / description

Previous value: -"TERYT county code (4 digits, e.g. 1465 = Warszawa). Longer codes (gmina/precinct) are truncated to the county. Wins over location when both are provided."New value: +"TERYT code. 4 digits = county (e.g. 1465 = Warszawa). 6 digits = dzielnica where available (today: Warszawa's 18 districts, e.g. 146510 = Śródmieście) → yield for that district. Other longer codes (gmina/precinct) are truncated to the county. Wins over location when both are provided."

AddedJul 7, 2026
RemovedJun 17, 2026

Changed1 schema field changedJun 11, 2026

addedInput schema / properties / areaBucket

Added value: +{
+  "description": "Apartment area range in m2: all (default, whole stock), 0-30, 30-40, 40-50, 50-60, 60-80, 80+. Bucket values are not additive.",
+  "enum": [
+    "all",
+    "0-30",
+    "30-40",
+    "40-50",
+    "50-60",
+    "60-80",
+    "80+"
+  ],
+  "type": "string"
+}

AddedMay 31, 2026

TDQS

A4.9/5.0

Behavior5/5

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

Annotations already declare readOnlyHint=true and destructiveHint=false, but the description adds extensive behavioral context: experimental beta status, may change/withdraw, methodology, suppression when samples <5, non-additive area buckets, market-based median exclusions, and approximation across data sources. It also discloses the 404 behavior for invalid locations. This goes far beyond what annotations provide.

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?

The description is long but every sentence earns its place. It is front-loaded with the beta warning and definition, then flows logically into methodology, limitations, parameter specifics, and edge cases. No filler or redundancy; the density is justified by the tool's complexity.

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?

The description covers most aspects an agent needs: scope, methodology, limitations, error conditions, and parameter semantics. However, it does not explicitly describe the output format (e.g., JSON fields, as_of date, yield value), which is a gap given there is no output schema. It mentions 'result is suppressed' and 'as_of dates' but does not state the return structure. This is a minor but notable omission.

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

Parameters5/5

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

Schema coverage is 100%, but the description adds substantial meaning: it explains teryt resolution (4-digit county, 6-digit dzielnica for Warszawa, truncation for longer codes), location name resolution (county-level cities, Warszawa districts, delegatura to parent county), and the non-additivity of areaBucket. It also gives concrete examples. This is far more than the schema alone.

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?

The description states the specific action ('Estimate the gross rental yield') and the exact resource (Polish city or county) with a clear formula. It distinguishes itself from siblings by computing a derived metric, and explicitly notes it is gross and top-line only. The purpose is unmistakable and unique among the sibling tools.

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

Usage Guidelines5/5

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

The description provides explicit when-to-use guidance: call list_rental_yield_locations first or pass a 4-digit county TERYT unless the location is known. It also gives clear exclusions: towns inside larger powiats, non-Warszawa districts, and osiedla will 404. It explains the teryt-vs-location precedence and warns about comparability across as_of dates. This is comprehensive usage routing.

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

All Cenogram - Polish Real Estate Data tools Inspect

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