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

With no annotations at all, the description has the full burden of behavioral disclosure. It goes beyond a pure label by disclosing round-trip behavior and the fact that per-segment availability flags for cabin, vehicles, pets, and e-ticket are returned. It is not exhaustive about pagination, errors, or read-only behavior, but it provides meaningful behavioral context.

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?

Two concise sentences with no filler. The core purpose is front-loaded and each sentence contributes additional relevant detail: one-way availability, round-trip support, and segment-level flags.

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?

It is complete enough to make a basic call using the required parameters, and the schema fills in param details. However, there is no output schema and no annotation, and the description does not say what happens with ambiguous location names, how the trip list is scoped, or how this differs from `ferryhopper_search_trips`. Given the number of sibling ferry tools, a little more context could be expected.

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 100%, so every parameter already has a clear meaning. The description adds round-trip behavior, but that is largely redundant with the `returnDate` parameter description. There is no extra parameter-level insight beyond the 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?

States a clear verb and object: get a list of ferry trips between two ports for a date, and mentions optional round-trip support. It is clear enough to select from most unrelated siblings, but it does not distinguish itself from the nearly identical sibling `ferryhopper_search_trips`, so it cannot receive a 5.

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 implies when to use it: for available trips between two ports on a date and for round-trip searches when a return date is given. It does not explicitly say when not to use it or name alternatives like `ferryhopper_trip_details` or `ferryhopper_get_direct_connections_for_ports`.

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