Fetch exact feature geometry as WKT by ID when shape matters, such as checking whether a route clears a building.
Fetch the exact geometry of features by id, as WKT. Use only when shape matters, such as checking whether a route clears a building.
| Name | Required | Description | Default |
|---|---|---|---|
| ids | Yes | ||
| scr | Yes | SCR document from a previous get_maplet. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It discloses that this is a read/fetch operation and that the response is WKT geometry, but says nothing about permissions, error behavior for unknown IDs, or whether it returns one or many geometries.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Two concise sentences, front-loaded with the action and output format, followed by a tightly scoped usage condition and example. Every sentence earns its place.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a simple two-parameter read tool with no output schema and no annotations, the description adequately covers what it returns (WKT geometry) and when to use it. Minor gaps remain around where IDs come from and error handling, but the core invocation context is present.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 50%: the 'scr' parameter is documented in the schema, while 'ids' is undocumented there. The description adds 'by id' and clarifies the fetched result is exact geometry, but does not explain the ID source or relationship to the SCR document.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb and resource ('Fetch the exact geometry of features by id') and adds the output format ('as WKT'). It also implicitly distinguishes itself from map-display siblings by saying to use it only when shape matters, so an agent can select it without opening other schemas.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
Gives explicit usage guidance with 'Use only when shape matters' and a concrete example ('checking whether a route clears a building'). It does not name the alternative tool to use for non-shape queries, so it stops short of fully explicit routing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.