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

Annotations already cover read-only, idempotent, open-world and non-destructive behavior, so the description is free to add value elsewhere — and it does, disclosing the response's breadth and time semantics ('weather now and this week', 'holidays in the next 30 days', 'with passport'). It does not state data freshness beyond those windows, upstream sources, or rate limits, which keeps it short of a 5.

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, front-loaded with the payoff ('Everything to know ... in one call') before the coverage list and the routing rule. The coverage enumeration is long but each item is a real capability, not filler; a bulleted or grouped phrasing would read slightly faster.

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 an output schema present the description need not explain return shape, and the annotations carry the safety profile, so the remaining job — telling an agent what topics the brief aggregates and when to prefer it — is done. The one gap is that it never warns the caller how broad the payload may be relative to a narrow sibling call.

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; the description earns a bump by tying the optional `passport` parameter to a concrete effect ('adds the entry rule and how long the person and the vehicle may stay'). Locale and country_code semantics remain entirely schema-side.

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?

Opens with a specific verb+resource+scope: everything to know before driving into one country by campervan or car, in one call. The enumerated coverage (entry rule, weather, fuel, tolls, holidays, hazards, plugs, customs, food prices) makes it unmistakable against the many single-topic siblings such as get_visa_rules or get_fuel_prices.

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?

Explicitly states the triggering intents (asking what to know about a country, the nuances, a guide, preparing a trip) and an explicit exclusion routing to 'the single-topic tools for one narrow question.' Alternatives are named as a class with the condition that selects them.

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