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

With no annotations, the description carries the full burden. It usefully discloses the return content and a behavioral cap (only the 10 cheapest-lead tested hypotheses are included), which is genuine beyond-schema information. However it says nothing about access requirements, whether results are cached/computed live, or how expensive the call is relative to the raw search tools.

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?

One dense sentence lists the returned fields first, then the parameter format, so it is front-loaded with the most decision-relevant content. It is a long enumerative sentence rather than clean prose, but nothing is wasted and nothing is padded.

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 must describe the return, and it does so field-by-field including units (USD) and the truncation to 10 hypotheses. Combined with 100% parameter coverage, an agent has enough to call it correctly; only error behavior and cost/auth context are absent.

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%, so the baseline is 3, and the description exceeds it by giving concrete literal formats for the single parameter ('biznes-prodazhi' or 'Бизнес'), clarifying that either a slug or a Russian display name is accepted. That is meaningful added value beyond the schema's terser 'slug or name, see list_niches'.

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 enumerates the specific payload returned (hypotheses, tested, worked, median CPC/CPS, budget, years, 10 cheapest-lead hypotheses), which is far more than a tautology and lets an agent distinguish it from list_niches or search_hypotheses. The pairing with the required 'niche' key makes the resource scope unambiguous. It lacks an explicit verb framing ('returns a summary for one niche'), but the resource and content are clear.

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?

No statement of when to use this versus list_niches (to discover niches) or search_hypotheses (to find hypotheses across niches). The only routing hint is the parameter note pointing at list_niches, which is incidental. An agent must infer that this is the per-niche aggregation endpoint.

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