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

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered; the description adds real value by disclosing what the output contains and that it 'Returns a link to the full roadbook the user can open, edit and share'. It does not mention that generation may be asynchronous or require polling get_roadbook_build_status, which is the one behavioral trait still hidden.

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?

Purpose is front-loaded and the trailing sentences about the returned link and the 'use this first' routing rule are well placed. The middle sentence is a long comma-heavy enumeration of outputs that is dense to parse, though each item does earn 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?

With an output schema present, return values need not be explained, yet the description still summarizes them; all 17 parameters are covered by the schema. The only meaningful omission is the async/roadbook-build workflow implied by the get_roadbook_build_status sibling, which the description does not address.

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% and all 17 parameters are individually documented with formats, enums, ranges and defaults. The description restates only the 2-10 waypoint bound and the budget categories, adding no syntax or semantics beyond the schema, so the baseline of 3 applies.

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 gives a specific verb and resource ('Plan a road trip by campervan or car between 2-10 places with the OpenVan.camp roadbook') and enumerates the concrete outputs (distance, driving time, day-by-day plan, budget, per-country entry rules, Schengen 90/180, LEZ stickers, holidays, plugs). It is clearly distinguishable from narrower siblings such as get_route_visa_rules, estimate_route_tolls or get_country_travel_brief, which cover only single slices of what this tool bundles.

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?

'Use this first when the user describes a trip from A to B' gives an explicit trigger and priority ordering relative to the sibling lookup tools. It stops short of naming when NOT to use it, and given the existence of get_roadbook_build_status it never explains the follow-up workflow if the roadbook is still building.

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