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

With no annotations, the description must carry disclosure, and it does: it spells out what comes back (next departures with 'from' price, itinerary with times, cabin categories, inclusions, exclusions for Italian departures, payment, link). It also adds a critical output-handling rule — always copy the WhatsApp booking link from the response verbatim. It does not discuss any limits or failure modes, so it is not exhaustive.

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?

Roughly half the text is marketing and pricing detail (990 €, 708 €, 728 €, specific dates) that the tool itself returns as content, not selection criteria. The actionable 'use this tool when…' clause sits in the middle of the paragraph instead of being front-loaded, though the final WhatsApp instruction is well-placed at the end.

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 zero-argument catalog tool with no output schema and no annotations, the description covers both what is returned and the crucial post-call behavior (copying the WhatsApp link). It does not clarify that the tool takes no query/filter input, which could leave an agent unsure how to handle a specific cruise request.

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 schema has zero parameters, so there is no parameter semantics to document and the baseline of 4 applies. Nothing in the description misrepresents inputs; the absence of any filtering arguments is implicit rather than explained.

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 names the exact resource — MSC cruises sold by Toda Canarias — and enumerates the concrete catalog (group cruise on MSC Fantasia, weekly Canaries/Madeira departures, anything else on quote), so an agent knows it is a cruise-information tool, distinct from the hotel/excursion/offer siblings. The core verb is only implied ('restituisce le prossime partenze'), buried mid-paragraph after marketing copy, which keeps it from 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?

It gives an explicit trigger list: use this tool when the customer mentions 'crociere, MSC, navi, cabine' or the Canaries cruise or the cruise with Luca and Selvaggia. That is strong routing guidance. It stops short of naming a sibling alternative or stating when NOT to use it, so it is not a 5.

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