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

Goes well beyond the annotations by disclosing the important semantic that omitted optional vehicle fields are cleared (not left untouched) and that empty km can stay derived, plus the five-minute token lifetime and the fact that nothing is applied. This is exactly the kind of contract a preview tool needs; only the follow-up/confirmation mechanics are thin.

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?

Three sentences, front-loaded with the action and immediately followed by the side-effect contract and the token/confirmation behavior. Slightly compressed phrasing ('empty km can remain derived') costs a little comprehension but nothing is wasted.

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?

No output schema exists, and the description does cover the return (exact preview plus confirmation token), which is the important part. It falls short on input semantics for three of the five nested fields and on how the confirmation token is consumed, so an agent could still mis-supply km values.

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 0% and the nested LoadVehicle object has five properties (trip_number, truck_reg, start_km, empty_km, closing_km) with only bare titles. The description clarifies empty_km's derived behavior and the omit-to-clear rule, which is useful, but start_km, closing_km, and truck_reg semantics are left entirely to the schema titles.

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 verb and resource: prepare (preview) replacing the truck/odometer record for a load, and explicitly says it does not apply the change. That differentiates it from the mutating sibling set_load_vehicle, though it never names that sibling.

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?

Clear that this is the preview step: 'Requires confirmation' and it returns a five-minute confirmation token rather than applying the change. It implies but does not state which tool to call with that token, so the workflow loop with set_load_vehicle is left to inference.

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