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Glama

Query Layer

query_layer
Read-onlyIdempotent

Query an ArcGIS Feature Service / Map Service layer by its url (from search_datasets). SQL-like where, comma-separated out_fields, order_by, limit, offset. Returns attribute rows (and geometry). Use where="1=1" + out_fields="*" to sample.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
urlYesFeature/Map Service layer url ending in /FeatureServer/<n> or /MapServer/<n>.
limitNoMax features (1-2000, default 50).
whereNoSQL where clause, e.g. "STATE = 'CA' AND YEAR >= 2020". Default "1=1".
offsetNoPagination offset.
order_byNoe.g. "POP DESC".
out_fieldsNoComma-separated field names, or "*" for all (default).

Schema Changelog

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

  1. Changed1 schema field changed
    • addedInput schema / examples
      Added value: +[
      +  {
      +    "limit": 50,
      +    "out_fields": "*",
      +    "url": "https://gis.fairfield.ca.us/arcgis/rest/services/OpenData/Parcels/FeatureServer/0",
      +    "where": "1=1"
      +  },
      +  {
      +    "limit": 100,
      +    "out_fields": "PARCEL_ID,ZONE_CODE,ACRES",
      +    "url": "https://gis.fairfield.ca.us/arcgis/rest/services/OpenData/Zoning/FeatureServer/0",
      +    "where": "ZONE_CODE = 'R1'"
      +  }
      +]
  2. First observed

TDQS

A4.4/5.0
Behavior4/5

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds behavioral context by noting that the query returns attribute rows and geometry, and by clarifying the SQL-like parameter semantics. No contradiction with 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?

The description is three sentences with no wasted words. It front-loads the purpose, then lists parameters in a compact format, and ends with a useful example tip. Every sentence contributes meaningful information.

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?

Given 6 parameters and no output schema, the description covers the essential aspects: what it does, the input pattern (URL from search_datasets), key parameter usage, and return type (attribute rows and geometry). It doesn't detail error handling or pagination beyond schema, but for a query tool with complete schema documentation, this is adequate. A slightly more explicit mention of pagination behavior would have made it a 5.

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

Parameters4/5

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

Schema coverage is 100% with descriptions for all 6 parameters, so the baseline is 3. The description adds value by grouping parameters (SQL-like where, comma-separated out_fields, etc.) and clarifying that output includes geometry, which is not explicitly stated in the schema. This enhancement pushes the score above baseline.

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 states the tool queries an ArcGIS Feature Service / Map Service layer by URL, distinguishing it from siblings like layer_info (which presumably describes layer metadata) and search_datasets (which finds datasets). The verb 'Query' is specific and the resource is well-defined.

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 by stating the URL comes from search_datasets, and it includes a practical sampling tip (where="1=1" + out_fields="*"). However, it does not explicitly mention when not to use this tool or name alternative tools for related tasks, so it stops short of full exclusion guidance.

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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TDQS

A3.5/5.0
Disambiguation2/5

Many tools have overlapping purposes, such as ask_pipeworx, ask_pipeworx_grounded, deep_research, and also multiple Polymarket tools (bet_research, polymarket_edges, polymarket_arbitrage). Descriptions try to differentiate but the boundaries are unclear, causing confusion.

Naming Consistency2/5

Naming conventions are mixed: some use snake_case (ask_pipeworx, query_layer), some use descriptive phrases (entity_profile, recent_changes), and there is no consistent verb_noun pattern. The variety makes it hard to predict tool names.

Tool Count1/5

33 tools is far too many for a server named 'Arcgis Fairfield', as most tools are unrelated to GIS or Fairfield (e.g., npm dependency checks, prediction markets, AI visibility). The tool count severely mismatches the server's purported scope.

Completeness1/5

The server's stated purpose is ArcGIS Fairfield, but only 3 tools (layer_info, query_layer, search_datasets) relate to that domain. Critical GIS operations like updating features or managing services are missing, while the vast majority of tools are for other domains.