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

With no annotations, the description carries the full burden and does substantial work: it discloses the price source hierarchy (manufacturer price list as source #1), the default coeffs (1.0/1.09/1.17), the computed outputs (3 offers, average, V, homogeneity V≤33%, НМЦК), and notes 'без файлов'. It omits auth/permission or failure behavior, but for a computation-only tool this is largely acceptable.

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?

Front-loads the purpose and the OR-alternative structure in a compact paragraph with no filler sentences; every clause carries information about inputs, defaults, or outputs. Dense but not bloated, though readability suffers slightly from packing many facts into one block.

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?

No output schema exists, but the description enumerates the return payload (offers, average, coefficient of variation, homogeneity flag, НМЦК), and all three parameters are covered. No annotations exist to fill gaps, yet the key facts an agent needs to call it correctly are present.

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 coverage is 100%, so the structured fields already document each parameter (baseline 3). The description adds real value beyond the schema: it clarifies that cart prices come from the manufacturer price list, that items carry the customer's own prices, and it supplies the concrete default coefficient values.

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?

States a specific verb+resource: computes НМЦК per art. 22 ФЗ-44 for any catalog cart or explicit items, and scopes it to the procurement agent with '(не только раздевалки)'. It implies a cart-variant distinct from the base calc_nmck but never names that sibling, so the differentiation is left partly to inference.

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?

Clearly lays out the two mutually exclusive input modes — cart:[{article,qty}] vs items:[{name,qty,price}] — and routes the agent to find_product for article lookup. It does not state when-not to use it or explicitly point to calc_nmck for the non-cart case, so the exclusion side is missing.

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