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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered. The description adds genuinely useful context beyond that: every mined keyword carries a defined market profile (search volume, growth, market space, competitor/seller counts, average price, cart-add conversion, top products) and that filtering is multi-dimensional — a good signal of result shape and cost of broad queries. It omits any note on rate limits, credit consumption, or result caps.

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 core purpose and return payload are front-loaded and useful, but the trigger list is bloated and self-duplicating ('Ozon keyword mining, Ozon keyword expansion' appear twice verbatim) and the 'etc.' after the filter enumeration weakens precision. Roughly a third of the text is redundant keyword stuffing that could be cut without losing meaning.

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 24-parameter tool with nested pagination and no output schema, the description carries the necessary load: it explains the seed-expansion behavior, the filter dimensions, and the fields of the per-keyword market profile. An agent has enough to call it correctly and interpret results; only the sibling-routing and result-limit details are missing.

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 100%, so all 24 parameters are already documented in the schema. The description enumerates the same filter dimensions (search volume, growth, product count, seller count, price, relevancy, title density, cart-add conversion) but adds no format, range syntax, or default guidance beyond what the schema states, so baseline 3 applies.

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?

Opens with a specific verb+resource ('mines Ozon related keywords around a seed keyword') and names the data returned (market profile per keyword), so the agent knows exactly what the tool produces. However, it never distinguishes itself from closely named siblings such as nexscope_ozon_keyword_back_search or nexscope_ozon_market_keyword_search, which also deal with Ozon keywords, so an agent cannot route between them from the description alone.

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?

States explicit use cases (keyword expansion, long-tail mining, seed keyword opportunity analysis) and a long list of trigger phrases plus a fallback ('even without explicitly mentioning Nexscope'). It stops short of the higher bar: no when-not-to-use conditions and no named alternative for adjacent tasks like reverse-ASIN keyword lookup.

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