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

Annotations already cover read-only, idempotent, non-destructive behavior. The description adds a useful behavioral detail with 'Cache 1h' and the endpoint. It does not explain open-world or open-ended result behavior, but no contradiction exists.

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 and front-loaded: it states the action first, then the endpoint, the use case, and the cache behavior. Every sentence adds value with no 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?

With an output schema present, return-value details are unnecessary. The description covers purpose, endpoint, use case, and caching. A minor gap is that it does not explain what happens when both optional item code parameters are omitted.

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%, with each parameter described as 'Códigos CATMAT a buscar' and 'Códigos CATSER a buscar.' The tool description reinforces that these are item codes and relates them to supplier discovery, but adds limited semantic detail beyond the schema.

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: 'Lista contratos e empenhos por itens (CATMAT/CATSER) no Comprasnet.' It clearly identifies the item-based supplier view and differentiates from the many sibling tools by focusing on discovering who currently supplies those items.

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 a clear intended use case: 'Útil para descobrir quem fornece esses itens hoje no governo (potenciais participantes em novos certames).' This is helpful context, though it does not explicitly name alternatives or exclusion criteria relative to sibling tools.

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