check_counterparty

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

No annotations are provided, so the description must carry the full behavioral burden. It does disclose the required environment variable and the kind of data returned, but it does not mention that this likely performs an external API call, how errors are handled, or explicitly state that the operation is read-only.

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 well-structured: the first sentence states the core purpose, followed by a one-line requirement and a clean Args spec. There is no filler or repetition of schema information.

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 single-parameter lookup tool with no output schema and no annotations, the description covers the input format and lists the main returned fields. It omits edge-case behavior (e.g., invalid INN, API errors) and the exact response structure, but the essentials are present for an agent to call it correctly.

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 0%, so the description is the only source of parameter meaning. The Args section specifies that 'inn' must be 10 or 12 digits, which adds real semantic value beyond the schema's plain string type. It could be richer (e.g., example or accepted formats) but is adequate for a single parameter.

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 uses a specific verb ('Возвращает') and names the resource (counterparty card by INN) plus the key data fields returned (status, head, address, registration dates). This clearly distinguishes it from the validation-focused siblings like validate_inn, though it does not explicitly call out any sibling.

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 states a prerequisite (DADATA_API_KEY) and implies the tool is used when you have an INN and need a counterparty card. However, it does not mention when to use this tool instead of parse_requisites or validate_inn, nor does it provide any exclusions or alternatives.

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