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

Annotations already declare readOnlyHint=true and openWorldHint=false; the description goes beyond them by disclosing return content (Virtuoso perk eligibility, a trip_id usable with get_trip_details, booking instructions) and by warning that no live rates are returned. A permissions/visibility caveat or result-ordering note would push this higher.

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?

Three short sentences: capability first, then result contents, then the rate caveat. Zero filler and no repetition of schema or annotation content.

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 usefully sketches what comes back (perks, trip_id, booking path) and warns about the missing rate data, which is enough for correct invocation alongside a fully documented 7-parameter schema. Minor gaps: no mention of default trip_type behavior or how to page, though limit/offset are schema-documented.

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 limit, offset, dates, trip_type enum, budget_usd and destination are all documented in structured form. The description's 'by place, brand or kind of stay' loosely echoes the destination parameter but adds no syntax or format detail beyond the schema, so the 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 and resource plus the exact inventory searched (2,000+ Virtuoso hotels, packages, cruises, private experiences) and the query axes (place, brand, kind of stay). It also separates itself from the rate-related siblings by declaring 'No live rates: the advisor quotes them,' and names get_trip_details as the follow-up, so an agent can route correctly without opening a 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 clear context for when to call it (discovery by destination/brand/stay type) and an explicit exclusion for live pricing, which routes rate questions to availability/quote tools. It stops short of naming those siblings directly, so the exclusions are implied rather than enumerated.

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