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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower; the description still adds real substance by disclosing the selection logic (up to three picks per port that fit the time ashore with an hour to spare before all aboard) and the per-port outputs (hours ashore, totals). It stops short of describing pagination or failure modes.

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?

Dense but front-loaded: what it returns, then the selection guarantee, then how to supply a sailing, then filters, then the sibling alternative. Every clause carries information, though the description packs several ideas into three long sentences.

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 does the work of explaining the return shape (hours ashore, up to three picks, per-port totals) and the cross-port filter behavior. Remaining gaps are minor for a read-only, idempotent lookup tool.

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 baseline is 3; the description goes further by clarifying that activity and minPrice/maxPrice narrow EVERY port rather than a single port, which is a cross-parameter behavior the schema does not express. The sailing-id-vs-ship/date relationship is also restated usefully.

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 resource (shore excursions), the scope (every port of one sailing, one call, itinerary order) and explicitly distinguishes itself from getPortExcursions. An agent can identify it without opening the schema.

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?

Gives both routing ('Use this instead of calling getPortExcursions once per port') and input alternatives (a sailing id from searchCruises, or ship plus sail date). When-to-use and which sibling to avoid are both explicit.

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