compras_pncp_modalidades

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

The description goes beyond the annotations by explicitly stating the tool is local and does not call upstream, which clarifies its behavior and performance characteristics. It also hints at the output structure by mentioning the `equivalente_dados_abertos` field, but does not fully describe the returned data; however, the read-only, idempotent, and non-destructive hints are adequately complemented.

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 concise and well-structured, using a title, a brief summary, and a bullet-pointed attention note to convey the key information about the two code tables. It avoids unnecessary detail while providing all essential context.

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?

The description provides complete context for a simple zero-parameter lookup tool: it explains the purpose, the source, the local behavior, and the relationship with other tools via the two-table warning. The output schema is available and the mention of the `equivalente_dados_abertos` field gives enough context for the expected result.

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 tool has no parameters, and the input schema is an empty object. Since there are no parameters to misinterpret, the description does not need to add any parameter semantics; the absence of parameters is clear and unambiguous.

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 identifies the tool as a local cheat sheet for PNCP contract modality codes. It states the source (official PNCP table under Lei 14.133) and explicitly distinguishes this code list from the Dados Abertos/SIASG enum, leaving no ambiguity about its purpose.

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 concrete usage guidance by warning about the two different code tables: it specifies that the `codigo` here is used in all `compras_pncp_*` tools and in the `modalidadeIdPncp` payload, while the Dados Abertos endpoint requires a different enum. It also notes that the tool is local and does not call upstream, implying it is appropriate for fast reference without external calls.

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