get_passenger_frequency

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

No annotations are provided, so the description carries the full burden. It only explains the metric (average daily passengers) but does not disclose whether data is historical/live, authentication needs, error handling, or an explicit read-only statement. The 'Return' verb implies read-only, but lacks context that would help an agent anticipate behavior.

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 two sentences, front-loaded with the core purpose and followed by usage guidance. No redundancy or filler; every sentence 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?

For a simple one-parameter tool with an output schema, the description covers purpose and usage triggers. However, it lacks caveats about data recency or station name matching, and there are no annotations to fill those gaps. It's reasonably complete but not perfect.

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 input schema fully describes the 'station' parameter with an example, giving 100% schema coverage. The description adds no additional parameter semantics beyond what the schema provides, so the baseline score of 3 is appropriate.

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 what the tool does: returns average daily passenger count ('how busy a Swiss station typically is'). It uses a specific verb ('Return') and resource, and it is distinguishable from sibling tools like get_stationboard (which provides schedules) and get_connections (which provides routes).

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 second sentence gives explicit triggers: 'Use this tool when the user asks "how busy is X?", "is it a major station?", or wants context for travel-time/connection planning.' This provides clear context but does not name alternatives or explicitly state when not to use, so it falls just short of a 5.

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