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

Annotations already cover the safety profile (readOnly, non-destructive, openWorld), so the bar is lower. The description adds real value by enumerating the returned metric families and noting that search position/visibility is optional, which matters given there is no output schema. It omits the T-1 data-delay caveat (left to the schema) and any mention of rate limits or per-niche coverage gaps.

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 purpose and capability sentences are front-loaded and efficient, but the trigger section balloons into a dozen near-identical keyword phrases ('Ozon trend, Ozon sales trend, Ozon price trend, Ozon daily data...') that add length without adding discriminative information. Roughly half the description is redundant keyword padding.

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 no output schema, the description does the necessary work of listing what the response contains (daily sales, price, stock, rating, optional visibility). Combined with the schema's date-range and T-1 delay notes, an agent has enough to call this correctly; only the niche-support caveat for search stats is left implicit outside the schema.

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 every parameter (dates, productId, includeFbs, includeSearchStats) is already documented in structured data. The description only echoes the date-granularity and optional search-visibility concepts without adding format, default, or interaction semantics. Baseline 3 is correct.

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 and resource with scope: 'single SKU daily time-series performance' for Ozon, enumerating the returned metrics (sales units, price, stock, rating, search position). This is far beyond restating the name. It does not distinguish itself from near-siblings like nexscope_ozon_product_detail or the duplicate nexscope_data_mp_ozon_product_trend, so it stops short of 5.

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?

Gives clear analytic contexts ('validating growth trends, seasonality, and anomaly detection') and a broad trigger list covering Ozon daily/stock/search-visibility intents, plus a fallback rule for implicit trend intent. However, it never names an alternative tool or states when NOT to use this one (e.g. vs. product_detail for a snapshot), so there is no exclusion guidance.

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