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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds useful behavior — it returns canonical model URLs and live-stock counts 'where available' — but says nothing about ranking, result ordering, or behavior when no stock exists beyond what the schema's liveStockOnly flag implies.

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 what is searched and what is returned; nothing is wasted. It is slightly padded by the full caravan/motorhome/campervan enumeration, which the schema's enum already carries.

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?

For a 7-parameter, no-output-schema tool the description does mention the return payload (URLs and stock counts), which compensates for the missing output schema. However, it omits routing guidance among the several search/listings siblings and any hint about result ordering or empty-result behavior, leaving meaningful gaps.

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 every parameter including berthsMin/berthsMax semantics, the limit hard cap and the enum are already documented in the schema. The description restates the facets (model, brand, vehicle type, berth range) without adding format or interpretation detail, 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 (search) and resource (active public RoamWorthy caravan/motorhome/campervan model research pages) plus the filterable facets, so the agent knows exactly what is being queried. It implicitly distinguishes itself from search_listings by scoping to 'model research pages', but it never names a sibling to make the boundary explicit.

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 implied by the facet list (search by model, brand, vehicle type, berth range), but there is no statement of when to prefer this over search_listings or find_matching_vehicles, nor any exclusions. The 'active public' qualifier hints at scope but does not guide tool selection.

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