compras_arp_consultar

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

Read-only and idempotent hints already cover the safety profile, and the description adds non-obvious behavior: malformed purchase-format IDs produce an explicit diagnostic instead of a silent `encontrada=false`, and results are cached for 15 minutes. These are meaningful behavioral details not available from 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?

Three short paragraphs with no filler: purpose, endpoint, output, edge-case behavior, and cache policy. Each sentence earns its place, and the most important information is front-loaded.

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 single-parameter read-only lookup, the description plus the rich schema and output schema cover everything needed: what it returns, how the input is identified, what happens on misuse, and caching behavior. Nothing required for correct invocation 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?

The schema already documents the single parameter with format, example, source field, and a warning about confusing purchase/ata IDs. The tool description adds further semantic value by explaining the failure behavior when the identifier uses the purchase-format, reinforcing why the `-NNNNNN` suffix matters.

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: 'Consulta uma ARP específica pelo identificador PNCP' and clarifies that it returns the complete ata header. The word 'específica' plus the PNCP identifier distinguishes it from the sibling list/search tools without ambiguity.

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 gives clear context for when to use this tool: to fetch one specific ARP by its PNCP ata identifier. The schema adds guidance on where the identifier comes from (compras_arp_por_fim_vigencia) and warns against confusing it with numeroControlePncpCompra, though it does not explicitly enumerate sibling alternatives.

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