census-mcp-server

Resolve Census Geography

census_resolve_geography

Read-only

Resolve a place name, ZIP code, or street address to Census FIPS identifiers. Converts names like "King County, WA", "Seattle, WA", or "Seattle-Tacoma-Bellevue, WA", and ZIPs like "98109", to the codes required by census_query_data and census_compare_geographies. Use before querying when you have a place name rather than raw FIPS codes — state_fips maps to parent_fips and fips_summary maps to geography_fips in downstream tools, and geography_type is itself the geography_level to query at.

Input Schema

Name	Required	Description
`name`	Yes	Place name (e.g., "King County, WA", "Seattle, WA", "California"), 5-digit ZIP code (e.g., "98109", resolved to its ZIP Code Tabulation Area), or street address (e.g., "1600 Pennsylvania Ave NW, Washington, DC 20500"). Include the state after a comma — its abbreviation or full name, as in "Chatham County, Georgia" — to disambiguate places with common names. It narrows a statistical area as well, matching any state the area spans, so "Kansas City, MO" and "Kansas City, KS" both reach the MO-KS metro area. Matching ignores case, reads "Saint" and "St." as the same word, and accepts unaccented spellings ("Dona Ana County, NM"). For a statistical area a leading city is enough ("Denver, CO" for the Denver-Aurora-Centennial metro area), and an older full name resolves through its leading city ("Denver-Aurora-Lakewood, CO"). A New York City borough with a New York suffix resolves to the county it is coextensive with when geography_type is "county" or omitted — "Brooklyn, NY" is Kings County, "Manhattan, NY" New York County, "Staten Island, NY" Richmond County. At any other level it is no_match, and at place, economic place, state, tract, or consolidated city the hint names the county.
`county_fips`	No	County FIPS code to resolve within — 1 to 3 digits, zero-padded here to the 3 the Census stores. A tract name is unique only inside its county, so a bare tract name matching two counties comes back as ambiguous_name until this is set: take the countyFips of the candidate you want from that error and re-call. Only county and tract sit within a county, so this restricts resolution to those two levels — pairing it with any other geography_type, or with a street address, is a county_scope_unsupported error rather than a scope quietly dropped. census_query_data takes the same code as its own county_fips but pads nothing, so hand it the 3-digit county_fips returned here, not the shorter value.
`geography_type`	No	Geography level to resolve to, named exactly as census_query_data's geography_level and census_list_geographies name it. Auto-detection covers only state, county, place, tract, and zip code tabulation area: zip code tabulation area for a 5-digit ZIP or ZIP+4 — the ACS's ZIP-shaped area, not cbp's "zip code" level, which takes the ZIP itself with no resolution — state for a two-letter abbreviation or a spelled-out state name, county when the name contains the word "County" or "Parish", county then place for the word "Borough" (an Alaska borough is a county, a PA or NJ borough a place), tract for the word "Tract", otherwise place (incorporated places and census-designated places together) with a fallback to county, where a census-designated place answers only when no incorporated place or county has the exact name — "Arlington, VA" is Arlington County, and set "place" to reach the Arlington CDP. The other four are never auto-detected and must be set explicitly, because their names overlap city names — "metropolitan statistical area/micropolitan statistical area" covers both metro and micro areas and yields a 5-digit code, "combined statistical area" yields a 3-digit code, "consolidated city" covers the eight merged city-county governments (Nashville-Davidson, Louisville/Jefferson County, Indianapolis, Athens-Clarke County, Augusta-Richmond County, Butte-Silver Bow, Milford CT, Greeley County KS), and "economic place" yields the 8-digit code ecnbasic 2022 publishes a place under: the 3-digit county it lies in (000 when it spans counties) followed by its 5-digit place code. Economic places are the incorporated places, census-designated places, and county subdivisions the 2022 Economic Census tabulates, plus each county's remainder ("Balance of Adams County, WA"). Setting it explicitly also overrides auto-detection — "New York" auto-detects as the state, so New York City needs "place".

Output Schema

Name	Required	Description
`name`	No	Canonical name of the resolved geography.
`error`	No	Present when the call failed. Absent on success.
`notice`	No	Present when the name was a New York City borough ("Brooklyn", "The Bronx", "Queens borough") resolved to the county it is coextensive with.
`place_fips`	No	5-digit place FIPS code when the resolved geography is a place — incorporated or census-designated. For an economic place, the place part of its 8-digit code, which is also the place code the 2017 and 2012 ecnbasic vintages take. For a street address, the incorporated place the address sits in (query it at the place level with state_fips as parent_fips); absent when the address is outside every incorporated place, and a census-designated place is never reported for an address.
`state_fips`	No	2-digit state FIPS code. Use as parent_fips in census_query_data for sub-state queries. Absent for a metropolitan/micropolitan or combined statistical area, which can span several states and needs no parent_fips, and for a zip code tabulation area, whose source layer carries no state.
`tract_fips`	No	6-digit census tract FIPS code when the resolved geography is a tract — from a street address, or from a tract name.
`county_fips`	No	3-digit county FIPS code when the resolved geography is a county or sub-county level.
`fips_summary`	No	Pre-formatted FIPS value ready to use as geography_fips in census_query_data (e.g., "033" for King County with state_fips "53" as parent_fips, "42660" for the Seattle-Tacoma-Bellevue metro area with no parent at all, "03363000" for Seattle as an ecnbasic 2022 economic place).
`geography_type`	No	Resolved geography level. Pass this straight through as geography_level in census_query_data and census_compare_geographies.
`block_group_fips`	No	1-digit block group within tract_fips, for a street address only. Query it as geography_level "block group" with this as geography_fips, alongside parent_fips, county_fips, and tract_fips. geography_type and fips_summary stay at the tract.
`census_designated_place`	No	Present (true) when the resolved place or economic place is a census-designated place (CDP): an unincorporated community the Census delineates for statistics, with no municipal government. Its code is queried like an incorporated place's. Absent for an incorporated place and every other level.

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedOct 13, 2026

changedInput schema / properties / name / description

Previous value: -"Place name (e.g., \"King County, WA\", \"Seattle, WA\", \"California\"), 5-digit ZIP code (e.g., \"98109\", resolved to its ZIP Code Tabulation Area), or street address (e.g., \"1600 Pennsylvania Ave NW, Washington, DC 20500\"). Include the state after a comma — its abbreviation or full name, as in \"Chatham County, Georgia\" — to disambiguate places with common names. It narrows a statistical area as well, matching any state the area spans, so \"Kansas City, MO\" and \"Kansas City, KS\" both reach the MO-KS metro area. Matching ignores case, reads \"Saint\" and \"St.\" as the same word, and accepts unaccented spellings (\"Dona Ana County, NM\"). For a statistical area a leading city is enough (\"Denver, CO\" for the Denver-Aurora-Centennial metro area), and an older full name resolves through its leading city (\"Denver-Aurora-Lakewood, CO\")."New value: +"Place name (e.g., \"King County, WA\", \"Seattle, WA\", \"California\"), 5-digit ZIP code (e.g., \"98109\", resolved to its ZIP Code Tabulation Area), or street address (e.g., \"1600 Pennsylvania Ave NW, Washington, DC 20500\"). Include the state after a comma — its abbreviation or full name, as in \"Chatham County, Georgia\" — to disambiguate places with common names. It narrows a statistical area as well, matching any state the area spans, so \"Kansas City, MO\" and \"Kansas City, KS\" both reach the MO-KS metro area. Matching ignores case, reads \"Saint\" and \"St.\" as the same word, and accepts unaccented spellings (\"Dona Ana County, NM\"). For a statistical area a leading city is enough (\"Denver, CO\" for the Denver-Aurora-Centennial metro area), and an older full name resolves through its leading city (\"Denver-Aurora-Lakewood, CO\"). A New York City borough with a New York suffix resolves to the county it is coextensive with when geography_type is \"county\" or omitted — \"Brooklyn, NY\" is Kings County, \"Manhattan, NY\" New York County, \"Staten Island, NY\" Richmond County. At any other level it is no_match, and at place, economic place, state, tract, or consolidated city the hint names the county."

addedOutput schema / properties / notice

Added value: +{
+  "description": "Present when the name was a New York City borough (\"Brooklyn\", \"The Bronx\", \"Queens borough\") resolved to the county it is coextensive with.",
+  "type": "string"
+}

Changed8 schema fields changedSep 25, 2026

changedInput schema / properties / geography_type / description

Previous value: -"Geography level to resolve to, named exactly as census_query_data's geography_level and census_list_geographies name it. Auto-detection covers only state, county, place, and tract: state for a two-letter abbreviation or a spelled-out state name, county when the name contains \"County\"/\"Borough\"/\"Parish\", tract when it contains \"Tract\", otherwise place with a fallback to county. The other three are never auto-detected and must be set explicitly, because their names overlap city names — \"metropolitan statistical area/micropolitan statistical area\" covers both metro and micro areas and yields a 5-digit code, \"combined statistical area\" yields a 3-digit code, and \"consolidated city\" covers the eight merged city-county governments (Nashville-Davidson, Louisville/Jefferson County, Indianapolis, Athens-Clarke County, Augusta-Richmond County, Butte-Silver Bow, Milford CT, Greeley County KS). Setting it explicitly also overrides auto-detection — \"New York\" auto-detects as the state, so New York City needs \"place\"."New value: +"Geography level to resolve to, named exactly as census_query_data's geography_level and census_list_geographies name it. Auto-detection covers only state, county, place, tract, and zip code tabulation area: zip code tabulation area for a 5-digit ZIP or ZIP+4 — the ACS's ZIP-shaped area, not cbp's \"zip code\" level, which takes the ZIP itself with no resolution — state for a two-letter abbreviation or a spelled-out state name, county when the name contains the word \"County\" or \"Parish\", county then place for the word \"Borough\" (an Alaska borough is a county, a PA or NJ borough a place), tract for the word \"Tract\", otherwise place (incorporated places and census-designated places together) with a fallback to county, where a census-designated place answers only when no incorporated place or county has the exact name — \"Arlington, VA\" is Arlington County, and set \"place\" to reach the Arlington CDP. The other four are never auto-detected and must be set explicitly, because their names overlap city names — \"metropolitan statistical area/micropolitan statistical area\" covers both metro and micro areas and yields a 5-digit code, \"combined statistical area\" yields a 3-digit code, \"consolidated city\" covers the eight merged city-county governments (Nashville-Davidson, Louisville/Jefferson County, Indianapolis, Athens-Clarke County, Augusta-Richmond County, Butte-Silver Bow, Milford CT, Greeley County KS), and \"economic place\" yields the 8-digit code ecnbasic 2022 publishes a place under: the 3-digit county it lies in (000 when it spans counties) followed by its 5-digit place code. Economic places are the incorporated places, census-designated places, and county subdivisions the 2022 Economic Census tabulates, plus each county's remainder (\"Balance of Adams County, WA\"). Setting it explicitly also overrides auto-detection — \"New York\" auto-detects as the state, so New York City needs \"place\"."

changedInput schema / properties / geography_type / enum

Previous value: -[
-  "state",
-  "county",
-  "place",
-  "tract",
-  "metropolitan statistical area/micropolitan statistical area",
-  "combined statistical area",
-  "consolidated city"
-]New value: +[
+  "state",
+  "county",
+  "place",
+  "tract",
+  "metropolitan statistical area/micropolitan statistical area",
+  "combined statistical area",
+  "consolidated city",
+  "zip code tabulation area",
+  "economic place"
+]

changedInput schema / properties / name / description

Previous value: -"Place name (e.g., \"King County, WA\", \"Seattle, WA\", \"California\") or street address (e.g., \"1600 Pennsylvania Ave NW, Washington, DC 20500\"). Include the state abbreviation to disambiguate places with common names — it narrows a statistical area as well, matching any state the area spans, so \"Kansas City, MO\" and \"Kansas City, KS\" both reach the MO-KS metro area. For a statistical area, the name is the full hyphenated one the Census publishes (\"Seattle-Tacoma-Bellevue, WA\" for the metro area, \"Seattle-Tacoma, WA\" for the combined one) — a single city name matches it too when only one area contains that city."New value: +"Place name (e.g., \"King County, WA\", \"Seattle, WA\", \"California\"), 5-digit ZIP code (e.g., \"98109\", resolved to its ZIP Code Tabulation Area), or street address (e.g., \"1600 Pennsylvania Ave NW, Washington, DC 20500\"). Include the state after a comma — its abbreviation or full name, as in \"Chatham County, Georgia\" — to disambiguate places with common names. It narrows a statistical area as well, matching any state the area spans, so \"Kansas City, MO\" and \"Kansas City, KS\" both reach the MO-KS metro area. Matching ignores case, reads \"Saint\" and \"St.\" as the same word, and accepts unaccented spellings (\"Dona Ana County, NM\"). For a statistical area a leading city is enough (\"Denver, CO\" for the Denver-Aurora-Centennial metro area), and an older full name resolves through its leading city (\"Denver-Aurora-Lakewood, CO\")."

addedOutput schema / properties / block_group_fips

Added value: +{
+  "description": "1-digit block group within tract_fips, for a street address only. Query it as geography_level \"block group\" with this as geography_fips, alongside parent_fips, county_fips, and tract_fips. geography_type and fips_summary stay at the tract.",
+  "type": "string"
+}

addedOutput schema / properties / census_designated_place

Added value: +{
+  "const": true,
+  "description": "Present (true) when the resolved place or economic place is a census-designated place (CDP): an unincorporated community the Census delineates for statistics, with no municipal government. Its code is queried like an incorporated place's. Absent for an incorporated place and every other level.",
+  "type": "boolean"
+}

changedOutput schema / properties / fips_summary / description

Previous value: -"Pre-formatted FIPS value ready to use as geography_fips in census_query_data (e.g., \"033\" for King County with state_fips \"53\" as parent_fips, \"42660\" for the Seattle-Tacoma-Bellevue metro area with no parent at all)."New value: +"Pre-formatted FIPS value ready to use as geography_fips in census_query_data (e.g., \"033\" for King County with state_fips \"53\" as parent_fips, \"42660\" for the Seattle-Tacoma-Bellevue metro area with no parent at all, \"03363000\" for Seattle as an ecnbasic 2022 economic place)."

changedOutput schema / properties / place_fips / description

Previous value: -"Place FIPS code when the resolved geography is an incorporated place."New value: +"5-digit place FIPS code when the resolved geography is a place — incorporated or census-designated. For an economic place, the place part of its 8-digit code, which is also the place code the 2017 and 2012 ecnbasic vintages take. For a street address, the incorporated place the address sits in (query it at the place level with state_fips as parent_fips); absent when the address is outside every incorporated place, and a census-designated place is never reported for an address."

changedOutput schema / properties / state_fips / description

Previous value: -"2-digit state FIPS code. Use as parent_fips in census_query_data for sub-state queries. Absent for a metropolitan/micropolitan or combined statistical area, which can span several states and needs no parent_fips."New value: +"2-digit state FIPS code. Use as parent_fips in census_query_data for sub-state queries. Absent for a metropolitan/micropolitan or combined statistical area, which can span several states and needs no parent_fips, and for a zip code tabulation area, whose source layer carries no state."

First observedSep 19, 2026

TDQS

A4.4/5.0

Behavior4/5

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safe-read profile is covered. The description adds value beyond that by spelling out output field mappings (state_fips → parent_fips, fips_summary → geography_fips, geography_type → geography_level), which is genuine downstream-behavior context. It does not add per-call constraints like ambiguity resolution, but the schema carries those.

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?

Three sentences, front-loaded with the purpose, then examples, then the when-to-use plus field-mapping guidance. No filler, though the middle example sentence is somewhat redundant with the examples already in the schema's name description.

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?

An output schema exists so return values need not be described; the rich schema documents all three parameters and the annotations cover the safety profile. What the description must supply — purpose, when to call it, and how its outputs feed the downstream tools — it supplies.

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?

With 100% schema description coverage the baseline is 3, and the description earns above it by explaining that geography_type is itself the geography_level downstream and by linking state_fips/fips_summary to the consumer tools' field names. That cross-tool parameter semantics is not present in the schema and directly aids correct invocation.

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 (resolve) plus resource (place name, ZIP, or street address → Census FIPS identifiers), and grounds it with concrete examples. The downstream framing against census_query_data and census_compare_geographies makes its role distinguishable from the other census_* siblings without opening any schema.

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?

"Use before querying when you have a place name rather than raw FIPS codes" gives a clear trigger condition and names the consuming tools. It stops short of an explicit when-not or of naming a competing resolver, but no such alternative exists among the siblings, so the guidance is practically complete.

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

All census-mcp-server tools Inspect

Try in Browser

One endpoint for every MCP toolRayrun runs every MCP server behind one URL and holds the credentials. Each call is decided per client, tool, and argument, then recorded.ray.runAd

Glama MCP Gateway

Add one secure layer between your agents and this server.