Station exits and facilities

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

Annotations already cover safety (readOnlyHint, openWorldHint), and the description adds genuinely non-obvious behavior: passing coordinates changes the ordering of results by distance. It also enumerates what the records contain. It does not mention truncation behavior beyond the schema default or what an empty/unknown station yields.

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 plus a compact example, front-loaded with what is returned and followed by the optional-parameter behavior. The first sentence is long and dense but every clause carries content; nothing is filler.

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?

With no output schema, the description takes on the return-shape burden and does so by listing exits, accessibility modes, and facility locations. Combined with a fully documented 5-parameter schema and read-only annotations, an agent has enough to call it correctly; only error/empty cases are unaddressed.

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 100%, so the baseline is 3; the description goes beyond it by explaining that lat/lon are the destination coordinates used for distance ranking, not a station filter — a semantic the schema does not convey. It also demonstrates valid system/station value shapes with a concrete example.

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 names the concrete resources returned — station exits with stair/escalator/lift status, plus lifts, toilets and information desks — for TRA, THSR and metro systems. It is clearly distinguishable from timetable/live-board siblings, though it never states that it is a single-station lookup rather than a search.

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?

Usage is only implied: the reader infers 'call this when you need to know how to get out of a station and what facilities it has'. The one explicit guidance is to supply lat/lon so exits are sorted by distance, with a worked example. No alternatives (e.g. rail_station_search) are named or excluded.

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