compras_arp_consultar

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

With no annotations, the description discloses important behaviors: it returns the header of the ata, handles edge cases (wrong input format returns diagnostic instead of silent failure), and mentions a 15-minute cache. It does not address authentication or side effects, but as a read operation on an open data endpoint, this is acceptable.

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 compact (4 sentences plus a line for endpoint and cache) and front-loaded with the main purpose. Every sentence adds essential information without redundancy or fluff.

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, the description need not detail return values. It covers the tool's purpose, parameter semantics, edge-case behavior, and cache policy. It is sufficient for an agent to decide when and how to use this tool correctly.

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?

The schema already provides 100% coverage for the single parameter. The description adds significant value by explaining the format with an example, warning against confusion with compra IDs, and detailing the behavior when the format is wrong. This goes beyond the schema's description.

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: 'Consulta uma ARP específica pelo identificador PNCP.' It specifies the verb (consultar), resource (ARP), and identifier type. This distinguishes it from sibling tools that list, search, or retrieve items of ARPs.

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 context for when to use the tool (consulting a specific ARP by PNCP identifier) and includes a specific guide on handling the input format (compra vs. ata format). However, it does not explicitly state when not to use this tool or mention alternatives among the sibling tools.

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