compras_arp_unidades_item

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

No annotations are provided, so the description bears the full burden. It discloses the endpoint, cache duration (15 min), and that it is from 'Dados Abertos', which implies read-only open data. However, it does not explicitly state read-only behavior, authentication needs, rate limits, or any side effects. The cache info adds value, but overall transparency is moderate.

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 consists of three sentences, each serving a distinct purpose: listing the output, providing the endpoint, explaining the function, and noting the cache. No redundant or vague language. It is front-loaded with the primary action and efficiently conveys all necessary information.

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 presence of an output schema (context signal: has_output_schema=true), the description does not need to detail return values. It covers the tool's purpose, endpoint, cache policy, and parameter distinctions. The mention of 'potenciais caronas' clarifies the output scope. No gaps are evident given the tool's simplicity and the rich schema.

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 the baseline is 3. The description adds meaningful value beyond the schema by clarifying that 'numero_ata' is distinct from 'numeroControlePncpAta' and suggesting to use the field from other tools. It also reinforces the purpose of the 'unidade_gerenciadora' parameter. This extra context justifies a score of 4.

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 lists 'UGs participantes (potenciais caronas) de um item da ARP', specifying the verb 'Lista', the resource 'UGs participantes', and the scope 'de um item da ARP'. It distinguishes from sibling tools like compras_arp_adesoes_item by adding 'potenciais caronas' (potential vs actual adhesions) and the endpoint reference, making the purpose unambiguous.

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 implicitly indicates usage: it 'determina quais unidades podem usar a ata como carona', suggesting it is for checking potential participants before actual adhesion. However, it does not explicitly state when to use this tool versus alternatives (e.g., compras_arp_adesoes_item for actual adhesions), nor does it provide exclusion criteria or prerequisites. The guidance is implied but not explicit.

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