bus_stopsFind WMATA bus stops near a latitude/longitude within an optional radius (meters). Returns stop ID, name, routes serving the stop, and coordinates.
| Name | Required | Description | Default |
|---|---|---|---|
| lat | No | ||
| lon | No | ||
| radius | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Input schema / examplesAdded value: +[
+ {
+ "lat": 38.8951,
+ "lon": -77.0369
+ },
+ {
+ "lat": 38.8951,
+ "lon": -77.0369,
+ "radius": 500
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "description": "Response from WMATA bus stops API",
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds that the tool returns stop ID, name, routes, and coordinates, which is useful but already implied by annotations.
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?
The description is a single sentence that immediately conveys the purpose and key details. No extraneous words.
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?
The description covers input (lat/lon, radius) and output (stop ID, name, routes, coordinates) adequately for a simple tool. An output schema exists, so full return details are not needed in the description. Minor omission: no mention of edge cases like no stops found.
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 0%, and the description only minimally explains parameters (lat, lon, radius in meters). It does not specify format constraints (e.g., decimal degrees) or limits (e.g., max radius), leaving room for ambiguity.
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?
The description specifies the action 'Find', the resource 'WMATA bus stops', and the key parameters (lat/lon, optional radius). It clearly distinguishes from sibling tools like bus_routes, bus_route_details, bus_incidents, and bus_predictions.
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?
The description clearly states when to use the tool (to find stops near a point). It does not explicitly exclude scenarios, but the context of sibling tools provides implicit differentiation.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.