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

Though readOnlyHint is already set, the description adds important behavioral context beyond that: daily quota tiers, exact limits for anonymous/free/paid users, and the fact that exceeding the quota returns isError with instructions. It also clarifies what the output contains (counts, sums, trends, top customers/regions) and what it deliberately omits (product prices).

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 tool description is a single dense block with all information front-loaded: purpose, kinds, output contents, exclusions, quotas, and error behavior. It is wordier than strictly needed, but each sentence contributes unique information and no paragraphs/embellishments are wasted.

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?

There is no output schema, so the description does the work of explaining return content: counts of purchases and contracts, sums, year trend, top customers/regions. It also explains the quota/error outcome and exclusions. Given the two-parameter complexity and readOnly annotation, this is sufficient for a competent agent to invoke the tool, though an exact response shape would be even better.

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% and both parameters are already documented, so the baseline is 3. The description still adds value by mapping each kind to its concrete format and providing realistic examples ('21.20.10', 'ibuprofen'), plus specifying the oddity that MNN codes are krasoft.ru slugs in Latin rather than simple classifier codes.

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 opens with a precise verb+resource statement: an aggregated market slice of state procurement by classifier code. It enumerates exactly which code types are supported (okpd2, ktru, mnn) and names sibling tools (search_purchase_objects, search_contract_specs) for what this tool explicitly does NOT provide, making differentiation strong.

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 states the tool's usage as an aggregated market snapshot and provides an explicit when-not-to-use case: product prices are not included and must be obtained from search_purchase_objects/search_contract_specs on a paid tier. It also gives concrete quota behavior for anonymous, free, and paid use, so an agent knows when it will fail.

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