ptv_departures

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

With no annotations provided, the description carries full burden. It only states the basic action without disclosing any behavioral traits such as return format, pagination, rate limits, or authentication requirements. The presence of an api_key parameter is not addressed.

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 a single sentence, which is concise but overly sparse. It front-loads the purpose but misses opportunities to add brief, essential details (e.g., required parameters, output) without significant length increase. It is acceptable but not exemplary.

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 complexity (5 parameters, required fields, no output schema, no annotations), the description is incomplete. It lacks any mention of return data, parameter explanations, or usage context, making it insufficient for reliable tool invocation.

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 only 20% (only route_type has a description). The tool description adds no additional meaning to any parameter, leaving the agent uninformed about stop_id, route_id, max_results, and api_key. This is inadequate given the low coverage.

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 verb 'Get' and the resource 'PTV departures for a stop,' distinguishing it from siblings like ptv_disruptions or ptv_search, which serve different functions. However, it lacks specifics about required parameters (stop_id, route_type) that would further clarify its purpose.

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?

No guidance is provided on when to use this tool versus its siblings (e.g., ptv_disruptions, ptv_stops_on_route). There are no exclusions, alternatives, or context hints, leaving the agent to infer usage without support.

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