check_station_facilities

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

Annotations already cover the safety profile (readOnly, idempotent, openWorld, non-destructive), so the bar is lower. The description still adds behavioral context beyond them: broken equipment is returned first, results carry an attribution line, and ambiguous station names produce a disambiguation list rather than a guess. It does not discuss error handling or rate limits, so not a 5.

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?

Front-loaded with the core purpose, then usage examples, then the explicit exclusion, then practical notes. Dense but each block serves a routing or invocation purpose; the closing ordering/attribution note is brief and 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 read-only tool with no output schema, the description conveys what comes back (each facility, its place, state and reason) plus ordering and attribution. With zero required parameters, the ambiguity-resolution behavior is also covered. Only the exact response shape and error cases are left implicit, keeping it from a 5.

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%, so the schema already documents all five parameters richly (including the limit ordering rule and the station-vs-eva_no exclusivity). The description adds little param-specific meaning beyond repeating the 50 cap and broken-first ordering, so the baseline 3 applies.

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+resource: whether lifts and escalators at a railway station/Stadtbahn stop are working, including place, state and reason. It explicitly distinguishes itself from get_train_departures and get_departures, so an agent can route correctly without opening any schema.

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 when-to-use triggers ('step-free access, broken lifts, wheelchair or pram') with real example queries, and an explicit when-not-to-use with named alternatives ('Do NOT use for departures, platforms or delays — call get_train_departures or get_departures'). Nothing is left to inference.

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