ipums-mcp

nhgis_list_data_tables

List every NHGIS data table across all datasets. Get paginated identifiers, descriptions, and universes to identify relevant data.

Instructions

List all available NHGIS data tables across all datasets. Returns paginated list of table identifiers, descriptions, and universe.

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_list_data_tables"
  }
}

Input Schema

Name	Required	Description	Default
`pageSize`	No	Results per page
`pageNumber`	No	Page number (1-based)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 3, 2026

TDQS

A4/5.0

Behavior4/5

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explicitly mentions that results are paginated and lists return fields (table identifiers, descriptions, universe), which informs the agent about the response structure and the need to potentially paginate. This is meaningful beyond the schema, though it omits details like rate limits or auth requirements.

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 exactly two sentences, front-loaded with the main action, and every word is informative. No unnecessary elaboration or repetition of schema details.

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?

For a simple listing tool with two well-documented parameters and no output schema, the description adequately covers the return values and pagination behavior. It does not explain how to handle multi-page results or what 'universe' means, but that is likely acceptable for this low-complexity tool.

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 coverage is 100% with both pageSize and pageNumber having descriptions. The tool description adds context about pagination ('paginated list') but does not provide additional parameter-specific meaning beyond what the schema already documents. Baseline 3 applies.

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 identifies the verb ('List'), the resource ('NHGIS data tables'), and the scope ('all available across all datasets'). It distinguishes from sibling tools like nhgis_list_time_series_tables and nhgis_list_shapefiles by focusing on data tables specifically.

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?

The description implies usage when the agent needs an unfiltered enumeration of all data tables, but it does not explicitly mention when to avoid this tool or direct users to alternatives like nhgis_search_data_tables for filtered queries. The context is reasonably clear but lacks explicit exclusions.

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