Tagesfahrplan

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

With no annotations, the description carries the full burden. It usefully discloses that stop names are fuzzy-resolved, that the date is interpreted in Europe/Berlin, and that no realtime data is involved, but it says nothing about ambiguous-stop handling, error behavior, or result volume/cap.

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 short sentences, each earning its place: purpose first, then the two parameters with their formats, then the scoping exclusion. No filler or 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?

For a simple two-parameter read tool with no output schema and no annotations, the description covers the essentials: what is returned in principle, parameter formats, timezone, and fuzzy matching. It stops just short of describing output shape or the omitted-date default.

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 0%, so the description must compensate, and it largely does: 'stop' is documented as accepting either a name or a stopPointRef with fuzzy resolution, and 'date' as YYYY-MM-DD in Europe/Berlin. The only gap is that 'date' is optional yet no default behavior (e.g. today) is stated.

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: it returns the daily timetable for a stop on a given date. The clause 'Echtzeit wird hier nicht abgefragt' implicitly separates it from the sibling 'departures', but no sibling is named, so differentiation requires inference.

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 a clear exclusions signal — realtime is not fetched here — which tells the agent when to look elsewhere. However, it never names the alternative tool (departures) nor states prerequisites, so the routing is implied rather than explicit.

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