mcp-singapore

singapore_convert_coordinates

Read-onlyIdempotent

Converts SVY21 easting/northing coordinates to WGS84 longitude/latitude, or reverses the conversion, for accurate location mapping within Singapore.

Instructions

Convert SVY21 easting/northing metres to WGS84 longitude/latitude or the reverse within Singapore. Uses SLA projection parameters; no API key.

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": {
      "from": "<from>",
      "x": "<x>",
      "y": "<y>"
    },
    "name": "singapore_convert_coordinates"
  }
}

Input Schema

Name	Required	Description	Default
`x`	Yes
`y`	Yes
`from`	Yes

Output Schema

Name	Required	Description	Default
`ok`	Yes
`data`	No
`error`	No
`status`	No
`sources`	Yes
`metadata`	No
`provider`	No
`warnings`	No
`served_at`	Yes
`error_code`	No
`source_url`	No
`dataset_url`	No
`catalog_metadata`	No
`catalog_snapshot_at`	No
`retry_after_seconds`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.2.0Oct 23, 2026

TDQS

A4.2/5.0

Behavior4/5

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

Annotations already establish read-only, idempotent, non-destructive, open-world behaviour, so the bar is lower. The description still adds real operational context: SLA projection parameters are used and no API key is required, which tells the agent this is a local computation with no auth prerequisites. It stops short of noting accuracy limits or valid coordinate bounds.

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 sentences, no filler, and the core purpose and units are front-loaded before the secondary detail about projection parameters and keys.

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?

An output schema exists, so return-value explanation is unnecessary; the description covers datum, units, scope and auth. Missing only boundary behaviour and the coordinate-order convention for the WGS84 input direction, which matter for a transformation tool but are secondary.

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 description coverage is 0%, so the description must carry the weight, and it does disambiguate the otherwise opaque 'x'/'y' as easting/northing in metres and ties 'from' to the direction of conversion. It does not spell out the axis order for the reverse case (whether x becomes longitude or latitude), which leaves one gap given the zero schema coverage.

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?

Specific verb (convert) plus both resources and formats: SVY21 easting/northing metres and WGS84 longitude/latitude, with a geographic scope (within Singapore). Nothing else in the sibling list performs a datum transformation, so the agent can identify it without opening the schema.

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 phrase 'or the reverse' implies direction is controlled by the input, and 'within Singapore' scopes applicability. But it never states when to prefer this over the nearby address-oriented siblings (e.g. singapore_reverse_geocode) or what happens outside Singapore's bounds. Usage is implied rather than prescribed.

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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