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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds only the phrase 'supported auction vehicles' and does not disclose pagination behavior, result shape, or the relationship semantics, but it does not contradict the annotations.

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?

The description is a single sentence with no filler and the action is front-loaded. However, the phrase 'related supported auction vehicles' is somewhat vague, and the brevity comes at the cost of semantic precision.

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?

The annotations and schema cover safety, identifier format, and pagination bounds, but the central concept of 'related' is never defined. An agent cannot tell whether related means same model, same location, similar specifications, or something else, which is a clear gap for a tool whose entire purpose depends on that relation.

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 only 50%: identifier is described as 'VIN or slug_vin accepted by the canonical vehicle detail endpoint,' but per_page has no description beyond min/max constraints. The tool description itself adds no parameter context, so the meaning of per_page and the precise role of identifier remain under-specified.

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 states a specific action ('Retrieve') and resource ('related supported auction vehicles'), so the basic purpose is clear. However, it does not define what 'related' means, and it does not explicitly differentiate itself from siblings like get_vehicle or search_auction_vehicles.

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?

There is no guidance on when to use this tool versus alternatives such as get_vehicle, get_vehicle_history, or search_auction_vehicles. The schema comment about the 'canonical vehicle detail endpoint' hints at identifier compatibility but does not explain when this tool is the right choice.

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