plan_trip

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

Without annotations, the description carries the burden and does so reasonably: it documents defaults (today, now, 3 results, ~2000m walk limit, no transfer limit, 0 penalty), explains arrive_by semantics, and clarifies transfer_penalty behavior. It doesn't discuss rate limits, permissions, or failure modes, but for a read-only planning tool this is substantial behavioral 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?

Front-loaded with a clear purpose sentence, then a structured Args block. Every line addresses a parameter. The only minor inefficiency is that the Arg lines are terse notes rather than flowing prose, but they are information-dense with no wasted sentences.

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 9-parameter planning tool with an output schema (so return values needn't be explained), the description covers all inputs adequately, including defaults and semantics for behavior-affecting options. It could mention that results are itineraries or any geographic limitations, but otherwise it is complete enough for an agent to invoke correctly.

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 description coverage is 0%, so the description must compensate fully—and it does. All 9 parameters get meaningful explanations: from_place/to_place accept stop names or coordinates with examples, date/time formats are given, and transfer_penalty's effect on routing preference is explained. This goes well beyond type signatures.

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 verb+resource+scope: 'Plan a public transport trip between two locations in Estonia.' This clearly distinguishes it from siblings like get_departures or search_stops, which handle departure/stop lookup rather than full trip planning.

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?

Usage context is implied by 'Plan a public transport trip between two locations in Estonia,' but there are no explicit when/when-not guidelines or named alternatives. An agent must infer that this is the tool for A-to-B routing versus, say, get_route.

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