Ставки, перекладываемые на плательщика

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

No annotations are provided, so the description must fully disclose behavioral traits. It mentions that only one rate is changed per call, which is a useful constraint, but it does not describe side effects (e.g., does it override existing rates?), reversibility, permission requirements, or error behavior. For a mutation tool, this is a significant gap – the description is too brief to fully inform the agent about what happens when the tool is called.

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 concise sentences with no fluff. The main action is front-loaded, and the key constraint (one method per call) and cross-reference to wata_terminal_rates are placed efficiently. Nothing extraneous.

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 simple mutation tool with three parameters and a clear purpose, the description covers the essential 'what' and 'how' (one method per call). However, it lacks details on the outcome (e.g., whether the rate is set absolutely or incrementally), any preconditions (e.g., terminal existence), or whether validation occurs. With no output schema and no annotations, the description leaves some ambiguity about the operational context. It is adequate but not complete.

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 each parameter (rate, terminalId, transactionType) already has a textual description. The tool description adds context by stating that the rate changes per method and that methods are listed in wata_terminal_rates, implying that transactionType should match one of those. This adds marginal value beyond the schema, but it doesn't explain rate format or allowed values beyond the schema's minimum=0. Baseline 3 is appropriate.

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's action: 'Задаёт, какая часть комиссии по конкретному методу оплаты перекладывается на плательщика' – it sets the portion of commission passed to the payer for a specific payment method. This is specific (verb+resource) and distinguishes it from the sibling wata_terminal_rates, which is referenced as the source for available methods. The purpose is unambiguous.

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 provides clear usage context: it explains that the rate is changed for one method per call ('Ставка меняется по одному методу за вызов') and directs the agent to wata_terminal_rates for available methods. While it doesn't explicitly say 'use this instead of that', it gives actionable guidance on how to properly invoke the tool, which is sufficient for this context.

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