get_departures

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

With no annotations, the description carries full burden. It mentions real-time data inclusion and defaults to current date/time, but lacks disclosure on side effects (though likely read-only), rate limits, authentication, or data freshness. It partially covers behavior but is incomplete.

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 concise with a clear main sentence and a structured Args section. Every sentence adds value, no fluff. It is front-loaded with the primary purpose.

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 the presence of an output schema, return value details are not needed. The description covers purpose, parameters, and included fields. It lacks error handling or edge cases (e.g., invalid station no departures), but is otherwise sufficient for a simple retrieval 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 0%, so the description fully compensates. It explains eva_no with an example and reference to find_station, and specifies date/hour format (YYMMDD, HH) with defaults. This adds significant meaning beyond the plain 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 clearly states the verb 'get' and resource 'timetable for a station within one hour slice', specifying real-time data like delays, platform changes, cancellations, and added trips. This distinguishes it from siblings like find_station (lookup) and get_live_changes/get_recent_changes (likely broader change tracking).

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 use for station departures and references find_station for EVA lookup, but does not explicitly state when to use this tool versus alternatives like get_live_changes or get_recent_changes. No 'when not to use' guidance is provided.

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