get_station_punctuality

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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, open-world), and the description adds genuinely useful behavior: the data source, the reporting window, and the definition of a delayed arrival (SBB flag, roughly 3+ minutes). It does not mention rate limits, data freshness beyond "previous operating day", or what happens when a station name is ambiguous, so not quite 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?

Three tight sentences: purpose and time window first, return payload second, normalization rule last. No filler, though the final sentence could be folded into the second to reduce 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?

With no output schema, the description correctly enumerates the returned shape (stop counts, arrival/departure delay counts, cancellations, delayed-arrival sample). For a read-only, idempotent lookup with full schema coverage that is nearly complete; only ambiguity handling for station names is 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 schema already documents station, line, limit, and contains. The description contributes only indirectly by explaining what counts as delayed, which gives meaning to the `limit` sample, but it adds no guidance on station-name matching or the contains/whole-name distinction.

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?

"Punctuality for an SBB stop on the previous operating day" names the resource (a stop's punctuality) and pins the data source (ist-daten-sbb target vs actual), so an agent knows exactly what it gets. It does not distinguish itself from plausible siblings such as get_station_passengers or get_departures/get_arrivals, which is the only thing keeping it from a 5.

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 one-day operating window is stated, which scopes usage implicitly, but there is no explicit when-to-use guidance, no exclusion (e.g. use get_departures for live/upcoming departures), and no note on what to do for stations not in SBB data. Adequate but leaves the agent to infer the boundary with sibling station tools.

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