Arrivals

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a live, side-effect-free read. The description adds a useful inventory of what the board surfaces (delays, platform changes, cancellations, messages), but says nothing about freshness, coverage window behavior, or failure modes for unknown stations.

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?

A single short sentence, front-loaded with the resource and enriched with the concrete data categories. No filler, no redundancy.

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?

An output schema exists, so return values need not be explained, and the annotations cover the safety profile. However, for a tool that requires a station identifier and competes directly with 'departures' and 'find_station', the absence of routing guidance leaves a real gap for an agent choosing between them.

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 75%, with 'hours' and 'start' already documented (including the Berlin-local ISO requirement), so the schema carries most of the load. The description adds no parameter meaning at all — notably nothing about the default one-hour look-ahead or the 100-row limit, which a caller might reasonably want framed.

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 gives a specific resource (arrival board) plus the data it carries: live delays, platform changes, cancellations and messages. It is clearly distinct from 'departures' by subject matter, though it never names that sibling, so differentiation is implicit rather than stated.

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?

There is no when-to-use guidance: nothing says to pick this over 'departures' for inbound trains, and nothing hints that 'find_station' should be used first to resolve a station name into an EVA number. The intended usage is only inferable from the tool name.

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