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cliwant

mcp-sam-gov

by cliwant

census_geographies_by_coordinates

Read-only

Resolve a latitude/longitude point to US Census geographies including state, county, tract, and block. Handles out-of-US coordinates gracefully.

Instructions

Resolve a longitude/latitude point → the Census GEOGRAPHIES at that point, no address parsing (US Census Geocoder, keyless; geocoding.geo.census.gov/geocoder/geographies/coordinates). For a caller that already holds coordinates. Input longitude/x (required, -180..180) + latitude/y (required, -90..90) — x=longitude, y=latitude (the Census API's own names; longitude/latitude are the clearer aliases), optional benchmark/vintage. Returns { found, coordinates:{x,y}, geographies:{ state, county, congressionalDistrict, censusTract, censusBlock, place, cbsaOrCsa, stateLegislativeUpper, stateLegislativeLower }, vintageResolved } + honest _meta. HONESTY: a point outside any US Census geography (offshore / out-of-US) ⇒ geographies all null / found:false / complete:true (an honest empty geographies:{}, NOT an error); coordinate finiteness is re-guarded PRE-fetch (a non-finite x/y ⇒ invalid_input, 0 fetch); a historical vintage's >1-layer-per-type is surfaced with alternates[] + a note (same [B1] multi-key handling as the address tool); GEOIDs are STRINGS (leading zeros survive); the resolved benchmark/vintage is echoed + a moving-vintage note; a bad benchmark/vintage ⇒ HTTP 400 THROWS; an outage/5xx ⇒ THROWS. MANDATORY CAVEAT every response: these are a NOMINAL input, NOT an authoritative HUBZone / Opportunity-Zone / set-aside determination.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
xNoLongitude — the Census API's own name for longitude (alias of `longitude`).
yNoLatitude — the Census API's own name for latitude (alias of `latitude`).
vintageNoGeography vintage (default Current_Current — a MOVING vintage; the same address may return a different tract/CD across cycles). The valid vintage set DEPENDS on the benchmark (a matrix — this enum is the UNION across all four benchmarks); an incompatible (benchmark, vintage) pair fails-closed with an HTTP 400 (invalid_input), never a silent mis-resolution. e.g. Census2020_Census2020 (with Public_AR_Census2020), Census2010_Current.
latitudeNoLatitude (y), a finite number in [-90, 90]. Alias of `y`. e.g. 32.377612.
benchmarkNoAddress-range benchmark (default Public_AR_Current — a MOVING benchmark). One of Public_AR_Current / Public_AR_ACS2025 / Public_AR_LUCA / Public_AR_Census2020. vintage MUST be compatible with this benchmark (a matrix); an incompatible pair fails-closed with an HTTP 400.
longitudeNoLongitude (x), a finite number in [-180, 180]. Alias of `x`. e.g. -86.301883.
Behavior5/5

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

Annotations already provide readOnlyHint and openWorldHint, but the description adds extensive behavioral details: honesty about null geographies for non-US points, coordinate finiteness check, vintage handling with alternates, GEOIDs as strings, moving vintage warnings, and mandatory caveats. No contradictions.

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

Conciseness3/5

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

The description is thorough but somewhat verbose, with sections like 'HONESTY:' that could be integrated more concisely. It is front-loaded with the purpose, which is good, but could be tighter.

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

Completeness5/5

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

Given the complexity (6 parameters, no output schema), the description is very complete. It covers edge cases (offshore, historical vintage, bad benchmark), mandatory caveats, and explains the return structure with geographies keys.

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 description coverage is 100%, baseline 3. The description adds value by explaining the x/y aliases, giving examples, and clarifying benchmark/vintage compatibility and defaults.

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 clearly states the tool resolves a longitude/latitude point to Census geographies, and distinguishes itself from address-based geocoding (sibling census_geocode_address). The verb 'resolve' and resource 'Census GEOGRAPHIES' are specific.

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?

It explicitly says 'no address parsing' and 'for a caller that already holds coordinates', indicating when to use. However, it does not explicitly compare to alternatives or state when not to use, though the implication is clear.

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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