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

With no annotations, the description carries the burden and does substantial work: it discloses the 5–30% band, volume floors, and sample-stability guard, so the agent knows results are aggressively filtered and small-magnitude moves are silently excluded. It also explains that moverScore is credibility-weighted (volume + sample stability) rather than raw magnitude, which prevents misreading the output; missing only sort order and cost/latency traits.

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?

Two sentences, zero filler, and the subject of the query is front-loaded ahead of the filtering and scoring caveats. Every clause carries information an agent cannot get from the schema.

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, and the description compensates by describing the returned entity (segment) and its moverScore field, plus the filtering that shapes results. It leaves the rest of the payload shape and the result ordering unspecified, which is the main remaining gap for a tool whose output is its whole value.

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 all four parameters already have descriptions and enum values, establishing a baseline of 3. The description adds context for two of them — it explains the ~30-day window that makes minThen meaningful and that ranking is on median price — but adds nothing for limit, country, or minNow beyond the schema.

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?

Names a specific resource (brand+model+fuel segments ranked by median price movement over ~30 days) and states the filtering/ranking logic, which is far more specific than siblings like get_market_trend or get_price_history. It stops short of explicitly naming which sibling answers a related question, but the resource itself is unambiguous.

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?

Usage is only implied: an agent can infer this is for spotting the biggest credible price shifts rather than tracking one vehicle or reading overall market stats. There is no explicit 'use this when... use get_price_history/get_market_trend instead when...' routing, so selection still requires inference.

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