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

Annotations already declare readOnly, idempotent and non-destructive, and the description adds real behavioral context on top: failure semantics ('dates are not available' when taken, 'listing_paused' when bookings are paused) and the guardrail that a quote is not a reservation. It does not describe the returned price structure or currency, but the error disclosure is genuinely beyond the annotations.

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, front-loaded with the output and input modes, then failure behavior, then the booking distinction. 'As its page shows it' is the only decorative phrase and it usefully signals the quote mirrors displayed pricing.

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 an 8-parameter read tool with no output schema, the description covers both input modes and the notable error codes, which is most of what an agent needs. The remaining gap is the shape of the returned quote (fields, currency, fee breakdown), which the description leaves implicit.

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 the baseline is 3, but the description adds a semantic fact the schema does not state: the two parameter families are alternative booking models (nights vs time slots), and it conveys that listing_id scopes the price to a single listing. This helps an agent pick the right date fields rather than passing an inconsistent mix.

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 (compute total price of a stay or a time slot at one listing) and gives both input modes by naming their fields. It also distinguishes itself from the booking flow with 'A quote is not a booking', which separates it from prepare_booking and get_booking_link without opening any 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?

Clear that this is for pricing a prospective stay/slot and explicitly not for committing a booking, which routes the agent away from prepare_booking. It stops short of naming the sibling to use instead when the user does want to book, so the exclusion is implied rather than explicit.

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