mbta_plan_trip

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

No annotations provided, so description bears full burden. It discloses return of 'optimal route options' but lacks details on data freshness, rate limits, error handling, or whether it supports real-time or historical data. Adequate but not thorough.

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?

Single sentence is maximally concise and front-loads the purpose. No redundant information.

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?

With 10 parameters, no output schema, and a description that does not explain parameter interactions or return format, the tool lacks completeness. It fails to convey that the output likely includes multiple itineraries, transit modes, or how to interpret optimality.

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 100%, so baseline is 3. Description adds no parameter-specific value beyond the schema. It mentions 'transfers, walking times, and real-time data' but does not elaborate on parameter roles like departure_time vs arrival_time.

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?

Description clearly states the verb ('Plan a trip'), resource ('MBTA public transit'), and output ('optimal route options with transfers, walking times, and real-time data'). It distinctly separates from sibling tools which are all data retrieval (alerts, schedules, etc.).

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?

Description implicitly defines usage by stating 'Plan a trip,' which sets clear context against sibling getters. However, it lacks explicit when-to-use or when-not-to-use guidance, such as scenarios better suited for other tools like schedules.

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