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

No annotations are provided, so the description carries the full behavioral burden. It does disclose two useful traits — deprecation status and that results are limited to one-way trips (no round-trip or multi-leg) — but says nothing about return shape, pagination, or failure behavior for a deprecated endpoint.

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 sentences, no filler. The deprecation and replacement tool are front-loaded, which is the single most decision-relevant fact for an agent, followed by the plain purpose statement.

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?

For a 3-parameter, no-output-schema tool with full schema coverage, the description supplies what structured fields cannot: deprecation, the replacement path, and the one-way scope limit. It stops short of return/pagination detail, but nothing essential to invoking it correctly is missing.

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 all three parameters are already documented in the schema (including the ISO date format and the 'name not port code' constraint). The description only restates the two-port/one-date shape, adding no new parameter semantics. Baseline 3 applies.

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 specific verb+resource+scope: 'Get a list of available one-way ferry trips between two ports on a specific date.' The 'one-way' qualifier and the named sibling ferryhopper_search_ferry_trips make it unambiguous which ferry search to pick.

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?

Explicitly marks itself deprecated and routes the agent to search_ferry_trips, stating exactly what that alternative adds (round-trip, multi-leg, per-segment availability flags). This is textbook when-to-use-which guidance.

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