mcp-geoes

describe_layer

Get a layer's schema details: field types, coded-value domains, geometry type, and record count. For WMS sources, states that no field schema is published.

Instructions

Describe a layer: fields with their types and coded-value domains, geometry type and record count. WMS sources publish no field schema and say so.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "source": "<source>",
      "layer_id": "<layer_id>"
    },
    "name": "describe_layer"
  }
}

Input Schema

Name	Required	Description	Default
`source`	Yes
`layer_id`	Yes

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 1, 2026

TDQS

A3.9/5.0

Behavior4/5

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

No annotations are provided, so the description carries the behavioral disclosure burden. It openly states that WMS sources publish no field schema and that the tool will say so, which is useful behavioral context. It does not discuss errors or permissions, but for an introspection tool with an output schema, the key behavior is disclosed.

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?

Two efficient sentences: the first front-loads the core purpose and output, and the second adds the important WMS exception. There is no redundancy or filler.

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 two-parameter tool with an output schema, the description adequately explains what the tool returns and highlights a source-specific limitation. It is slightly incomplete because it leaves parameter provenance and sibling-tool selection to inference, but those gaps are not severe.

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

Parameters2/5

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

With 0% schema description coverage, the description needed to clarify source and layer_id, but it does not explain their formats, origins, or how they relate to other tools. The mention of 'WMS sources' gives a small hint, but an agent still has little guidance on what values to provide.

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?

Uses a specific verb and resource ('Describe a layer') and enumerates the exact return payload: fields with types, coded-value domains, geometry type, and record count. This clearly distinguishes it from siblings like describe_service and query_layer. The WMS caveat further sharpens the tool's scope.

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 intended use is implied: call this when layer metadata or schema is needed. However, it does not explicitly mention when to prefer this over describe_service, list_services, or get_legend, nor does it state exclusions or selection criteria.

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

Deploy Server