Plan a public transport trip

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states what the tool returns ('trip patterns with legs, modes, durations, and realtime times'), which is useful, but it does not mention whether the operation is read-only, any rate limits, error handling, or what happens when no route exists. It also does not disclose external API dependencies beyond the Entur name. This is a partial disclosure, not comprehensive.

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 with no redundant wording. The first sentence establishes the tool's core purpose and service, while the second succinctly covers endpoint specification, optional settings, and output. Every clause contributes useful information, and the most critical scoping statement ('point-to-point') is front-loaded.

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 tool with 11 parameters and no output schema, the description covers the key calling conventions: endpoint types, optional time/mode/walk speed settings, and the shape of the return value. It does not explicitly explain that each endpoint can be independently given as either Stop Place ID or coordinates (the phrasing 'either as a Stop Place ID or as coordinates' could be read as a collective choice), nor does it mention that only one of the two origin specifications should be provided. However, the schema itself clarifies these details, so the description is largely sufficient.

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 schema description coverage is 100%, so the baseline is 3. The description adds value by explaining that endpoints can be provided either as Stop Place IDs or as coordinates, which clarifies the relationship between the from_place/to_place parameters and the latitude/longitude fields. It also mentions that departure/arrival time can be set, transport modes filtered, and walk speed changed, which maps to the optional parameters and provides context beyond the schema's field-level descriptions.

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 the tool's purpose: planning a point-to-point public transport journey in Norway, backed by Entur JourneyPlanner. It specifies the verb 'plan' and the resource 'public transport journey', and the phrase 'point-to-point' distinguishes it from sibling tools like get_departures which handle single-stop departures. The description is specific and unambiguous.

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 description gives context on how to provide endpoints ('either as a Stop Place ID or as coordinates') and mentions optional parameters, but it does not explicitly state when to use this tool versus alternatives such as get_departures or resolve_stop_place. There is no exclusionary guidance like 'for single-stop departures use get_departures instead', so the usage context is implied rather than explicitly routed.

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