Чем платить за поездку

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

Besides the existing readOnlyHint, idempotentHint, and non-destructive annotations, the description adds a clear semantic warning: 'Ничего не платит и ничего не меняет' - it neither pays nor mutates anything. This is valuable because the tool name may sound like an actual payment action, and the description prevents that misunderstanding. No contradiction with annotations was found.

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?

Two compact sentences cover purpose, key output topics, and the critical no-payment/no-mutation behavior. It is front-loaded and every phrase earns its place; there is no irrelevant detail or redundancy.

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?

The tool is a simple read-only lookup, has an output schema, and explains the required amount parameter, so a basic call is feasible. The optional account_id is not explained, and there is no explicit context about where in the travel booking flow this tool should be invoked. Overall, the description conveys the main usage but leaves minor ambiguity about optional parameters and triggering conditions.

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?

The required amount parameter is documented meaningfully: its source, the fact that it should be taken from flight_offer() or train_book(), and that it is non-mutating. However, account_id is completely undocumented, and the schema provides no description, so only half of the parameter space is actually covered by the description.

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 explains that this tool shows payment options for a trip: available accounts, bonus write-offs, cashback, and installment plans. It is clearly not a payment action and the final sentence explicitly clarifies it pays nothing. However, it lacks a direct verb like 'returns' or 'lists', and it does not explicitly distinguish itself from sibling tools such as train_pay or pay_bill by name.

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 amount parameter is tied to flight_offer() and train_book(), and the description warns that the tool does not pay or change anything. This gives a reasonable hint of when to use it, but there is no explicit 'use this before payment' or 'do not use this when the user wants to pay; use pay_bill/train_pay instead.'

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