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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered elsewhere. The description adds two useful behavioral facts the annotations lack: results are ordered best-first, and the response includes the leaderboard's page link. It says nothing about how ties are broken or what happens when limit exceeds available ships.

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?

A single front-loaded sentence with the ranking behavior first and the metric variant second; nothing is padded. The trailing phrase about the page link is slightly vague but still earns its place as return-content 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 only two optional parameters, full schema coverage, and annotations covering safety and idempotency, this description supplies everything else an agent needs: ordering semantics, the two modes of 'by', where to get metric slugs, and one return-field hint. No meaningful gap remains for a tool of this simplicity.

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 the baseline is 3, but the description goes beyond it by explaining that 'by' accepts either the overall default or one metric and by routing the agent to get_ship_metrics for slug discovery — a pointer absent from the schema. The 'best first' ordering also implicitly explains that limit truncates from the top of the ranking.

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-plus-resource (rated cruise ships, best first) and the scope (overall or a single metric), which separates it from the unranked list_cruise_ships sibling. It stops short of naming that sibling explicitly, so the differentiation is implied rather than stated.

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 parenthetical pointer to get_ship_metrics tells the agent where to find valid metric slugs, which is real usage help. There is no guidance on when to choose this over list_cruise_ships or get_cruise_ship, and no mention of when a metric-specific ranking is inappropriate.

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