Баланс аккаунта

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

The description provides concrete behavioral details: it returns the balance, Amount is a string in account currency (not micro-units), and a negative Amount indicates debt. This complements the readOnlyHint and idempotentHint annotations, giving a full picture of the tool's side-effect-free behavior.

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 moderately detailed but well-organized. It covers purpose, uniqueness, field format, negative meaning, and parameter usage in a logical sequence. Some extra context (e.g., 'deprecated service') is included but does not detract from clarity.

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 description lists the returned fields, explains the currency format, and clarifies the default account behavior. Since no output schema is provided, this textual description compensates well. It lacks error-handling details or edge cases, but for a simple read-only balance retrieval, it is sufficiently 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?

The input schema has a single parameter 'logins' with its own description explaining it defaults to the token's account. The tool description repeats this information without adding significant new semantics. Since schema coverage is 100% and the description adds no extra meaning, a baseline score of 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 returns the balance and financial fields, specifying the exact fields (Amount, AmountAvailableForTransfer, Currency, Discount, AccountID). It also distinguishes this tool as the only Yandex Direct API that provides balance, highlighting its unique purpose among siblings.

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 explains the default behavior (returns the token's own account balance) and how to request specific accounts by passing the 'logins' parameter. It also notes that this is the sole API for balance, making it clear when to use this tool rather than alternatives.

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