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

Annotations only declare readOnlyHint and openWorldHint; the description carries the real behavioral burden. It defines what the prices numerically represent (total for the whole stay, one room, in the requested currency, Nuitee as merchant of record, taxes Nuitee collects included) and separates property-paid taxes into taxes_at_property, plus explains the purpose of book_url. This is exactly the context an agent needs before quoting prices.

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?

Information-dense with no filler, and the returned payload is front-loaded before the pricing caveats. The first sentence is an unusually long run-on with nested parenthetical enumerations, which hurts scannability, but every clause carries substantive meaning.

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 fully owns explaining the return shape and does so thoroughly (hotel fields, offer fields, pricing, taxes, book_url). Minor gaps remain: it never says what happens if no dates are passed for availability, and it doesn't point to prebook for continuing the booking flow.

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 seven parameters are already documented, which sets the baseline at 3. The description restates the currency default and the fact that prices are per-room totals, but adds no new syntax or constraint detail for adults, children, dates, or nationality beyond what the schema already provides.

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 ('One hotel's details') and enumerates the exact fields returned, including room offers when dates are supplied. It is distinguishable in substance from search_hotels and the booking siblings, though it never names an alternative explicitly.

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?

Usage is only implied by the conditional clause 'when dates are given, every bookable room for them', which hints at the two operating modes. There is no explicit guidance on when to call this versus search_hotels (to find hotel_id) or prebook (to obtain a booking token), so the agent must infer the workflow.

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