XMLStock: wordstat

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

Annotations are present (readOnlyHint: false, openWorldHint: true), so the description's burden is lower. The description adds key behavioral context: it is a paid service (~19₽/1K) and provides the exact return shape, including both 'results' (top phrases) and 'associations' (similar phrases). This goes beyond what annotations convey. No contradiction with annotations.

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 description is compact yet information-dense. It front-loads the cost warning, then the return structure, then the operator syntax — all in three sentences. No filler; every sentence earns its place.

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 paid tool with no output schema, the description covers the essential behavioral details: cost, return format, and query language. It does not mention error handling, rate limits, or authentication requirements, but the sibling *_auth_status and set_credentials tools cover auth. Given the openWorldHint and annotations, the description is quite complete for an agent to call it correctly.

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 67%, and the query parameter lacks a description in the schema. The description compensates by explaining Wordstat operators ("...", !, +, -, [ ], |) in the query. Region and account are already described in the schema, so this is a strong contribution. The description makes the query parameter's syntax clear.

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 clearly states the tool's function: returning Yandex Wordstat frequency and top queries via XMLStock. It specifies the return structure ({ totalCount, results, associations }) and even lists supported Wordstat operators. This distinguishes it from sibling tools like xmlstock_wordstat_dynamics (trends over time) and xmlstock_wordstat_regions (geographic data).

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 states when to use this tool — when you need wordstat frequency and top queries — and includes a cost warning ('ПЛАТНО за запрос'). However, it does not explicitly exclude alternatives like dynamics or regions, nor does it mention when NOT to use it (e.g., for trends use wordstat_dynamics). The 'when' is implied but alternatives are not named.

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