list_routes

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

No annotations are provided, so the description carries the full burden. The verb 'Get' and the phrase 'Supports optional filtering' disclose read-only behavior and filter support, but the description does not mention response structure, route identifiers, or edge cases like empty results. That is acceptable for a simple listing tool but not rich disclosure.

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 front-loaded sentence: it states the core action first, then the optional filtering behavior. The enumeration of line names and bus routes is somewhat redundant with 'all routes' but remains compact and useful for clarifying scope.

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 tool is simple: one optional parameter, no required arguments, and no nested objects. The description supplies the geographic scope, route categories, and filter capability, which is enough to invoke it correctly. The lack of an output schema means response field details are not described, but that is a minor gap for a basic list-all-routes tool.

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 100%, and the input schema already documents the optional query parameter with examples. The description only restates that filtering is supported, adding no meaning beyond the structured schema.

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 states a specific verb ('Get') and resource ('all Metro Transit routes'), with geographic scope and route categories. Brother tools like get_route_directions, get_route_stops, and get_departures are clearly narrower, so list_routes is easily distinguishable as the route-catalog tool.

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 implies usage when a full or filtered route list is needed, and the optional query hint gives some context. However, it never explicitly says when to use this tool versus siblings such as search_stops, and it provides no when-not-to-use guidance.

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