ipums-mcp

nhgis_create_extract

Request an NHGIS extract by specifying datasets, time series tables, shapefiles, and output format; get an extract number and status to generate reproducible R or Python code.

Instructions

Submit a new NHGIS extract request. Specify datasets (with data tables and geographic levels), time series tables, shapefiles, and output format. Returns the new extract number and initial status. Once submitted, use nhgis_extract_to_code to generate reproducible R or Python code for the extract.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "nhgis_create_extract"
  }
}

Input Schema

Name	Required	Description
`datasets`	No	Map of dataset name to dataset specification
`dataFormat`	No	Output data format
`shapefiles`	No	Shapefile identifiers to include
`description`	No	Human-readable description of the extract
`timeSeriesTables`	No	Map of time series table name to specification
`geographicExtents`	No	Geographic extents to filter by

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 3, 2026

TDQS

A4/5.0

Behavior3/5

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

With no annotations, the description carries the burden of behavioral disclosure. It reveals that the tool returns an extract number and initial status, implying asynchronous processing. It does not cover permissions, side effects, or validation behavior, but the core create-and-return semantics are communicated.

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 three sentences, front-loaded with the primary action, and every sentence adds value: what the tool does, what it returns, and the recommended next step. No wasted words.

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 input schema is rich with nested objects and 100% parameter descriptions, and the description covers the essential orientation: what to specify, return value, and follow-up. It does not explicitly note that all parameters are optional, but the schema's required fields (none) already convey that. For a complex tool with strong schema support, this is adequately complete.

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 description coverage is 100%, so the baseline is 3. The description lists the main parameter categories (datasets, time series tables, shapefiles, output format) but adds no syntax or structural detail beyond what the schema already provides.

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 uses the specific verb 'Submit' and clearly identifies the resource as 'NHGIS extract request'. It distinguishes from siblings like microdata_create_extract by naming NHGIS and lists the key inputs (datasets, time series tables, shapefiles, output format), establishing a distinct purpose.

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?

The description provides clear context for NHGIS extract creation and explicitly points to nhgis_extract_to_code as the follow-up step, which guides sequential usage. However, it does not explicitly mention alternatives or exclude microdata_create_extract, though the NHGIS naming makes the scope clear.

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