platform_departures

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

With no annotations, the description carries the behavioral transparency burden. It usefully discloses the live-vs-booked platform matching logic and the caveat that a booked platform can change. It doesn't cover every possible behavioral aspect like authentication or error cases, but for a simple read-style query tool this is strong 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?

Two sentences with no filler. The primary scope and time window are front-loaded, and the important matching caveat is added in the second sentence. Every part 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?

The core domain nuance (platform assignment can change) is disclosed, and an output schema exists to define return values. It could be more explicit about choosing this over related sibling tools, but for a single-platform departure query it provides enough context for correct selection and invocation.

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?

The schema already documents 'station' and 'platform' with meaningful descriptions, while 'count' has constraints but no explicit semantic description. The tool description adds no parameter-level detail beyond what the schema provides, and schema coverage is moderate at 67%, so this is adequate but not enriched.

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 resource ('one platform') and behavior ('next trains leaving') with a clear time horizon ('next ~2 hours'). This distinguishes it from sibling tools like live_departures, which imply station-wide departures, and departure_platform, which focuses on determining a train's platform.

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 clearly implies usage: use this when you need departures from a specific platform within about two hours. However, it does not explicitly state when not to use it or name alternatives such as live_departures or departure_platform, so the guidance is implied rather than prescribed.

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