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

There are no annotations, so the description carries the full burden. It does disclose the return shape (matching models, in-stock first, plus an explanation of the selection rules) and frames itself as a preliminary pick, which is useful. It never states whether this is read-only/no side effects, whether prices are live, or any rate/availability caveats for a tool that queries a live catalog.

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?

Purpose is front-loaded in one sentence, followed by a compact parameter glossary and a closing caveat about measurement. Every line is informative; the dense em-dash parameter run is slightly harder to scan than a list, but nothing is redundant.

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 an 8-parameter, no-output-schema tool, the description covers nearly everything an agent needs: intent, per-parameter meaning, ranking behavior, and the measurement follow-up. Only the limit parameter and output format details (units, structure of the 'explanation') are left unspecified.

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% across 8 params, so the description must compensate, and it largely does: it enumerates object_type values, explains operators (МТС, Билайн, МегаФон, T2), bands_mhz, need (calls|internet|both), ready_kit semantics, and max_price in rubles. The only undocumented parameter is limit, and the need enum is given only in prose while the schema declares it as a bare string.

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 opening line states a specific verb and resource: selecting equipment variants for a given object (дача, офис, склад...). That is clearly distinct from the generic catalog/search siblings, though it never names the alternative tools explicitly. An agent can grasp the goal without reading the schema, but the boundary versus usilitel_products_search is left implicit.

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 gives real selection logic: bands_mhz from a measurement override operators when known, ready_kit switches between kits and repeaters, and it advises offering a signal measurement as the next step. There is no explicit 'use this instead of X' routing to the sibling search tools, which keeps it below a 5.

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