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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds real value beyond that by disclosing the return content — vehicle classes, vignette durations, concession sections, verification date and source — which is meaningful with no output schema present.

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?

A single front-loaded sentence that names the resource first and then enumerates content. Dense but every clause carries information; no filler or repetition.

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 appropriately characterizes what is returned, including data provenance (verification date and source). It stops short of stating coverage limits (e.g. whether all countries are supported) or locale behavior, but is largely sufficient for a reference lookup.

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 both country_code and locale are fully documented in the schema. The description adds only the scoping notion of 'one country' and does not explain the locale parameter's effect, so it stays at the baseline.

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 resource and scope: a toll reference for one country, enumerating the content (per-km rates by vehicle class, vignette prices, concession sections, bridges/tunnels). This differentiates it implicitly from route-based siblings like estimate_route_tolls, though it never names an alternative.

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 single-country scope implies when this lookup is appropriate versus estimate_route_tolls, but there is no explicit when-to-use, when-not, or named alternative. Usage must be inferred from the scope phrasing.

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