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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description reinforces this with 'Ничего не бронирует' and adds the pricing-rule context ('публичного pricing/quote'), but does not disclose the response shape or any failure modes. With annotations carrying the safety burden, this is adequate value-add but not rich.

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 tight sentences: purpose first, then the required parameter constraints, then the non-booking disclaimer. No filler or repetition.

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 read-only check tool with no output schema, the description covers the calling contract (inputs, formats, non-mutating nature) well and hints at the return (price via pricing/quote rules). It stops short of describing what the availability result actually contains, which would be the last useful detail.

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 0%, so the description must compensate, and it does: it pins date to YYYY-MM-DD, start_time to HH:00/HH:30 in Europe/Moscow, and duration_hours to the discrete set 1/1.5/2/2.5/3 (stricter than the schema's plain 1–3 range). This is exactly the format/timezone/allowed-value information the schema omits.

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 (Проверка availability and price for a boat) and explicitly ties the input to the sibling: boat_id comes from search_boats. An agent can immediately tell this is the follow-up step after search_boats, not a search itself.

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?

Implies the correct calling sequence by requiring boat_id 'из search_boats', routing the agent to the sibling first. It also clarifies that nothing is booked, so an agent does not mistake it for a reservation step. It lacks an explicit when-not clause, but the context is clear.

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