plan_journey

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

No annotations are provided, so the description carries full burden. It describes the purpose and parameters but lacks details on behavioral traits such as error handling, real-time nature, or optional intermediate stops. This is acceptable but not exhaustive.

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 concise with a leading sentence and an Args list. It is front-loaded with purpose and efficiently covers parameters. Slightly wordy but overall effective.

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?

Given the tool has 5 parameters and an output schema, the description adequately covers inputs and purpose. It does not detail return values or error conditions, but the output schema likely handles that. Minor omissions prevent a 5.

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 fully compensates by explaining each parameter: from_location/to_location (postcode, station, address), via (optional), time (ISO or HH:MM), and time_is_arrival (boolean). This adds significant meaning beyond the raw schema.

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 it plans a journey between two locations in London using public transport, which is a specific verb and resource. It distinguishes itself from sibling tools, none of which are journey planners.

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 implicitly indicates when to use this tool (for journey planning in London via public transport). While it doesn't explicitly state when not to use it, the context signals show no similar tool among siblings, so differentiation is adequate.

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