Macrostrat

Find Columns

find_columns

Read-onlyIdempotent

List Macrostrat stratigraphic columns near a geographic point. Provide lat and lng (decimal degrees). Returns the columns covering that location with column name, regional group, coordinates, unit count, and area. Keyless.

Example tool call

This call uses example arguments supplied in the tool’s input schema.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "lat": 40.8071,
      "lng": -104.9901
    },
    "name": "find_columns"
  }
}

Input Schema

Name	Required	Description	Default
`lat`	Yes	Latitude (decimal degrees).
`lng`	Yes	Longitude (decimal degrees).

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedJul 29, 2026

addedInput schema / examples

Added value: +[
+  {
+    "lat": 40.8071,
+    "lng": -104.9901
+  }
+]

First observedJun 9, 2026

TDQS

A4.3/5.0

Behavior4/5

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

Annotations already cover the read-only, idempotent, and non-destructive nature. The description adds value by noting 'Keyless' and listing the exact return fields, which provides useful behavioral context beyond the annotations.

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?

Three concise sentences, front-loaded with the tool's purpose, and every sentence adds relevant information. No fluff or redundancy.

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?

For a simple two-parameter read-only tool with no output schema, the description adequately covers what it does, the inputs needed, and the structure of the result. It is complete for the tool's complexity.

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 clear descriptions for both lat and lng. The description only repeats 'Provide lat and lng' without adding semantic meaning beyond what the schema already provides, earning the baseline score.

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 a specific verb 'List' with a clear resource 'stratigraphic columns' and geographic scope 'near a geographic point'. It distinguishes itself from siblings like find_units by explicitly naming the resource type.

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?

States the required inputs (lat/lng) and notes that it is keyless, giving clear usage context. It does not explicitly name alternatives or exclusions, but the context is sufficient for a simple lookup tool.

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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