rail_stationsReturn all WMATA Metro rail stations, optionally filtered by line_code. Returns station code, name, line codes served, and latitude/longitude.
| Name | Required | Description | Default |
|---|---|---|---|
| line_code | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Input schema / examplesAdded value: +[
+ {
+ "line_code": "RD"
+ },
+ {
+ "line_code": "BL"
+ }
+]Output schema / (root)Previous value: -nullNew value: +{
+ "description": "Response from WMATA rail stations API",
+ "type": "object"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the description's mention of returning stations adds little beyond what's already known. No additional behavioral context (e.g., rate limits, pagination, or data freshness) is provided.
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 sentences, each serving a purpose: first states action and filter, second lists return fields. No redundancy, optimally front-loaded.
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?
Given annotations and output schema (present but not shown), the description covers the main purpose and parameters. However, it lacks details about default behavior (e.g., what happens if no line_code is specified) or response format, though the output schema may address this.
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 coverage is 0%, but the description compensates by clearly explaining the optional line_code parameter and what it filters. This adds meaning beyond the bare schema definition.
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 clearly states the tool returns all WMATA Metro rail stations with optional filtering by line_code. It lists specific output fields (station code, name, line codes, lat/lng) and distinguishes it from sibling tools like rail_station_info and rail_lines.
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 mentions optional filtering by line_code, implying usage for either all stations or by line. However, it does not explicitly state when to use this tool over siblings like rail_station_info or rail_lines, nor does it provide exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.