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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint. The description adds value by explaining the output includes an itemised breakdown and the amount payable now, which informs the agent about the response nature. It does not contradict annotations and provides useful context beyond the safety hints.

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?

The description is two sentences with no redundancy. It front-loads the core purpose ('itemised price') and then gives the usage context ('before starting the booking'). Every word contributes, making it efficient and easy to parse.

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 pricing tool with full parameter documentation and no output schema, the description is complete. It states what the tool returns (itemised price, total, amount payable) and when to use it. No critical information for an agent to call it correctly is missing.

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. The description mentions 'chosen extras' and 'discount or voucher code' which roughly maps to the extras, discount_code, and voucher_code parameters. However, it does not add detailed semantics beyond what parameter descriptions already convey, such as formats or constraints.

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 clearly states the tool produces an 'itemised price for one accommodation, stay and party, including chosen extras and any discount or voucher code.' This is a specific verb (get/price), resource (accommodation stay), and scope (with extras and discounts), which distinguishes it from siblings like check_availability (which checks availability) and start_booking (which initiates a booking).

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?

The description explicitly says 'Use it to show the guest the exact total and the amount payable now before starting the booking.' This gives a clear temporal context (before booking) and purpose (show total/payable amount). It doesn't explicitly name alternatives or exclusions, but the context is sufficient to differentiate from siblings.

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