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rteina

geoparquet-mcp

by rteina

geoparquet_filter_spatial

Find features inside a rectangle or WKT area and return them as GeoJSON. Filter by category, name, or confidence to get exactly the matching places, using pushdown to read only relevant data.

Instructions

Return the features of a dataset that fall inside an area, as a GeoJSON FeatureCollection. The area is either a lon/lat rectangle or an arbitrary WKT geometry.

WHEN TO USE IT. When the answer is the features themselves — "which cafes are in this neighbourhood", "give me the buildings along this street" — and you intend to look at them individually. When you only need a count, a ranking or a distribution, use geoparquet_aggregate_attribute or geoparquet_summarize_h3 instead: they answer from the remote file and transfer kilobytes instead of features.

COST. The rectangle is what makes the read cheap. It is pushed into the remote Parquet file and prunes whole row groups from their footer statistics before any byte of data is fetched, so a tight box costs far less than a wide one — this is the difference between megabytes and gigabytes, not a micro-optimisation. Always pass the tightest area the question allows.

PARAMETERS. source: dataset name. min_lon, min_lat, max_lon, max_lat: the rectangle, in WGS 84 degrees. Pass all four, or none if you are using wkt. wkt: an arbitrary geometry instead of a rectangle, for example 'POLYGON ((2.33 48.85, 2.36 48.85, 2.36 48.87, 2.33 48.87, 2.33 48.85))'. Its envelope prunes the read and the exact shape then filters the survivors, so the answer is exact. Give either a rectangle or a wkt, never both. category: exact match on the dataset's category column, for example 'restaurant'. Preview the column first — the vocabulary is not obvious. name_contains: case-insensitive substring of the feature name. min_confidence: 0 to 1, Overture's own confidence in the record. 0.8 drops most questionable entries. columns: column expressions to return. A narrow projection is worth as much as a tight box, because Parquet is columnar and unread columns are unfetched. include_geometry: false skips the geometry column — the widest in the file — and approximates each feature by its bounding-box corner, which is exact for points. Ignored when wkt is used, since the exact test needs the geometry. limit: maximum features, capped at 1000.

WHAT COMES BACK. geojson as a FeatureCollection; feature_count and truncated, which tells you the limit was reached and there is more; geometry_is_exact; the sql that ran; and scan with bytes_scanned — read it, and tighten the area if it looks large.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
wktNo
limitNo
sourceNooverture_places
columnsNo
max_latNo
max_lonNo
min_latNo
min_lonNo
categoryNo
name_containsNo
min_confidenceNo
include_geometryNo

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault

No arguments

Schema Changelog

Changes observed during successful MCP inspections. Dates show when Glama detected each change.

  1. First observedv0.1.0

TDQS

A5/5.0
Behavior5/5

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, and it exceeds expectations. It explains cost behavior, how rectangle pruning works in Parquet, how WKT envelope pruning plus exact filtering works, the effect of include_geometry, and the exact contents of the response including bytes_scanned as a diagnostic signal.

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 long but every section earns its place: purpose, when-to-use, cost rationale, parameter semantics, and return value explanation. Clear section headers and front-loaded main behavior make the length navigable, and there is no filler or repetition.

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 12-parameter spatial filter tool with no annotations and no schema-level descriptions, the description is remarkably complete. It covers all inputs, output shape, behavioral nuances, cost implications, and alternatives, leaving no meaningful gap an agent would need to guess about when selecting or invoking the tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters5/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate entirely for the parameter semantics. It does so thoroughly: every one of the 12 parameters is explained, including constraints like 'Pass all four, or none', the mutual exclusivity of rectangle vs wkt, the meaning of min_confidence, the columnar cost benefit of columns, and the limit cap of 1000.

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 opens with a specific verb and resource: 'Return the features of a dataset that fall inside an area, as a GeoJSON FeatureCollection.' It also clarifies the two possible area forms (rectangle or WKT), and the WHEN TO USE IT section names the exact sibling tools that cover other use cases, distinguishing this tool clearly.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly states when to use this tool ('when the answer is the features themselves') and when not to use it ('when you only need a count, a ranking or a distribution, use geoparquet_aggregate_attribute or geoparquet_summarize_h3 instead'). It also gives practical guidance on passing the tightest area, which directly informs tool invocation.

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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