Get Vehicle Holders

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

Beyond the annotations (readOnly, openWorld, idempotent, non-destructive), the description discloses key behavioral traits: it returns separate awardees and earners lists with counts, explains that the counts can be wildly different, and clarifies that vehicle_family.piids rolls up every related PIID so awardee_count reflects the whole family, not just the queried PIID. This is critical behavioral context that annotations do not provide and that an agent must know to interpret results correctly.

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 long but well-structured: it opens with the core distinction, then provides business context, parameter details, and return behavior. Every sentence adds needed information, especially since schema coverage is 0%. It is slightly verbose but not wasteful; a compact but dense layout earns a 4.

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?

Given the tool's complexity (two distinct lists, family rollup, Pro-only restriction, parameter sources) and that an output schema exists, the description provides all necessary context for an agent to call it correctly and interpret results. It covers the business rationale, parameter origins, output structure, and the family rollup caveat. Nothing essential 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 description coverage is 0%, so the description must carry the parameter semantics. It explains piid as the 'vehicle's own PIID (from search_vehicles or get_contract_vehicle)' and limit with 'max 250'. While it doesn't fully specify what limit applies to (likely both lists), it gives a concrete bound and source, which is valuable beyond the bare schema. Slight ambiguity about the exact effect of limit prevents a 5.

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 clearly states the tool's purpose: 'Get who holds a vehicle AND who's actually earning through it' – a specific verb and resource. It distinguishes between two distinct populations (holders vs. earners) and explicitly says not to conflate them. It also ties the purpose to a concrete business question ('can I even compete for this work'), making it unambiguous and distinct from sibling tools like search_vehicles or get_contract_vehicle.

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 provides clear context on when to use it: it's the 'can I even compete for this work' answer on a multi-award vehicle, and only holders can bid task orders. It also mentions the Pro-only restriction and refers to search_vehicles or get_contract_vehicle as sources for the input PIID. However, it does not explicitly list alternatives or state when not to use it, so it falls just short of a 5.

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