wsdot_ferry_terminals

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

Annotations already provide readOnlyHint=true, so the safety profile is covered. The description adds some behavioral context by indicating the data is 'current' and includes estimated wait times for drive-up customers. However, it does not disclose details like data freshness, update frequency, or any limitations beyond what is implied. No contradiction with annotations.

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 and front-loaded with the main action ('Get current terminal wait times') followed by a clarifying second sentence. Every word adds value, and there is no redundancy or filler.

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 no output schema, the description must convey what the agent can expect from the response. It covers the key data elements: terminal wait times, vehicle space availability, fullness per sailing, and drive-up wait estimates. Given the tool's simplicity (zero parameters, read-only), this is sufficient, though it could mention whether it covers all terminals or only specific ones.

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 tool has zero parameters, so there are no parameter semantics to elaborate. The description compensates by explaining what the returned data contains (wait times, space availability, fullness), providing value beyond the empty schema. Baseline 4 for zero-parameter tools is appropriate.

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 function: 'Get current terminal wait times and vehicle space availability at Washington State Ferry terminals.' It also specifies what data is shown (fullness, drive-up wait times), which distinguishes it from sibling tools like wsdot_ferry_schedule (schedules) and wsdot_ferry_vessels (vessels).

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 provides clear context for when to use the tool: when current terminal wait times or vehicle space availability at WSDOT ferry terminals is needed. It does not explicitly name alternatives or exclusions, but the domain context plus sibling tool names imply the intended use case.

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