Get Vehicle Detail

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

The annotations already mark the tool read-only and non-destructive, and the description adds valuable behavioral nuances: the vehicle_family block counts sibling PIIDs rather than listing them, rollups are scoped to this PIID only, and the 999999999999 ceiling is FPDS's placeholder for unlimited. This goes well beyond the structured 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 front-loaded with the core purpose and stays tightly organized around the single parameter and the most important return-value caveats. Every sentence adds meaning; the bulleted parameter note and the warnings are directly actionable.

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 one-parameter read-only tool with an output schema and safety annotations, the description covers the essential operational details: input provenance, family-scoping trap, and the ceiling placeholder. Nothing needed to call it correctly is missing.

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 0%, so the description carries the full burden. It clearly defines piid as 'vehicle's own PIID' and instructs the agent where to source it. This is more useful than most schema titles could be.

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 verb and resource: 'Get one contract vehicle's detail' and enumerates the returned facets (ceiling, period, what's been ordered). It also distinguishes itself from get_vehicle_holders by explaining the different meaning of vehicle_family data, so an agent can confidently tell them apart.

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?

The description tells the agent where to obtain the required piid parameter ('from search_vehicles or get_contract_vehicle') and explicitly routes to an alternative ('use get_vehicle_holders for the real family-wide count') when a family-wide scope is needed. This is clear when-to-use and when-not-to-use guidance.

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