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

No annotations exist, so the description carries the burden. It notes pricing (official API, $0.01 USDC) but does not disclose error behavior, result format, or whether a live external call is made. The term 'официальный API' implies a network call, but this is not explicit.

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?

One dense sentence, immediately states the core value proposition and pricing; no fluff. The price note is useful for an agent planning tool usage.

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?

With 7 parameters and no output schema or annotations, the description omits enough context for correct invocation—especially allowed values of mail_type/mail_category, the meaning of indices, and units of weight.

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?

Input schema coverage is low (no descriptions), and the description only clarifies the meaning of 'between indices' (from_index/to_index) and, implicitly, tariffs. It adds nothing about weight, mail_type, mail_category, declared_value, or their allowed values, leaving the agent to rely on parameter names and defaults.

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 identifies the resource (Russian Post) and the purpose (delivery cost and times between postal codes), plus cost/pricing info. It is specific enough to distinguish the tool from its pochta_* siblings, though it doesn't use an explicit verb like 'calculate'.

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?

No guidance on when to use this tool versus the alternatives (pochta_address, pochta_zip, etc.), no prerequisites, and no mention of index format requirements or edge cases.

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