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ajwann

Charlotte Open Data MCP Server

by ajwann

Query any dataset

query_dataset
Read-onlyIdempotent

Fetch records from any ArcGIS portal dataset layer using a SQL filter, optionally near a place within a set radius.

Instructions

Fetch records from any portal dataset layer with a SQL filter, optionally near a place.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
nearNoOptional street address or 'latitude,longitude'; when given, only records within radius_miles of it are returned.
limitNoMaximum number of records to return.
whereNoSQL where clause over the layer's fields (see describe_dataset), e.g. "ZIP = '28205'" or "DATE_REPORTED >= TIMESTAMP '2026-01-01 00:00:00'". Use '1=1' for everything.1=1
fieldsNoFields to return; omit for all.
order_byNoe.g. 'DATE_REPORTED DESC'.
layer_urlYesArcGIS layer URL from search_datasets, ending in /MapServer/<n> or /FeatureServer/<n>.
radius_milesNoUsed with near.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
notesNo
sinceNoEarliest date included (local time).
recordsYes
locationNo
breakdownNoCounts of all matching records per value.
breakdown_byNo
radius_milesNo
total_matchingYesRecords matching the filters; may exceed returned.

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

B3.3/5.0
Behavior3/5

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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description adds the geospatial behavior ('optionally near a place') and the SQL-filter capability, but says nothing about result caps, projection cost, or error behavior on bad layer_urls.

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?

One tight sentence with the primary action and the two optional capabilities front-loaded and zero filler. Nothing is redundant or padded.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The output schema covers return values and the annotations cover safety, which lightens the description's load. However, for a high-fan-out generic tool facing many specialized siblings, the missing guidance on routing between this and the get_*_near tools leaves a real gap.

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 every parameter including where, near, radius_miles, limit, and layer_url is already documented in the schema. The description only gestures at the SQL filter and proximity options without adding syntax or format detail, so baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (Fetch) and resource (records from any portal dataset layer) and names the two filtering modes (SQL filter, optional proximity). It is clearly the generic record-retrieval tool, but it never explicitly distinguishes itself from the specialized get_*_near siblings or from the other dataset tools (describe_dataset, summarize_dataset), which the schema itself cross-references.

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

Usage Guidelines2/5

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

There is no when-to-use or when-not guidance. Given a fleet of purpose-built siblings (get_crime_near, get_street_closures, get_traffic_crashes_near, etc.), the description should say whether this generic query is preferred, a fallback, or a substitute — it does not.

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