Баланс аккаунта

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the description doesn't need to restate safety. It adds contextual behavior: it distinguishes real money from bonus money (bonus spendable only on ads), clarifies it's a snapshot not a history stream, and explicitly states it does not top up the account. These details go beyond the annotations and give the agent useful behavioral nuance. Lacks info about rate limits or caching but that's minor for a read-only balance call.

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 compact and front-loaded: it states the purpose (returns balance), specifies both fields, explains the limitation (snapshot not history), and clarifies it does not top up. Every sentence adds value, and it doesn't repeat annotation info. No fluff.

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 no-argument read tool, the description covers purpose, return values, temporal scope, and non-actions (no top-up). It also gestures to alternative tools (statistics) without needing to name them. The lack of an output schema is mitigated by the description explicitly stating the two fields and their meaning. Nothing essential 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?

There are zero parameters and the schema is empty. The description confirms 'Аргументов не принимает' (takes no arguments), which is helpful confirmation given the empty schema. The baseline for a zero-parameter tool is 4, and the description meets it; there is nothing else to explain.

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 current balance of a configured advertising account, distinguishes between real money (balance) and bonus money (bonusBalance), and explicitly notes it takes no arguments. It names specific fields returned with their semantics, making the purpose unambiguous. It stands apart from sibling tools like get_account (which likely returns account details) and the stats tools by stating this is a balance snapshot.

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 tells the agent when to use it (current balance snapshot) and when not to: 'это срез на текущий момент, не история — расход за период дают инструменты статистики' (this is a snapshot, not history — spending over a period is provided by statistics tools). It also clarifies it does not top up the account, steering agents away from it for funding operations. This is explicit when/when-not guidance, rivaling the calibrations example.

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