get_ipca

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

With no annotations, the description carries the full burden. It clearly states the output unit (monthly variation percentage) and explains the meaning of the 'ultimos' parameter (number of months). However, it does not specify the response format (single value vs. series), which is a minor gap.

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 extremely concise, using two compact clauses to convey the purpose and parameter meaning with no filler. The key information is front-loaded and every word earns its place.

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 covers the core purpose and parameter, but without an output schema it omits the exact return structure (e.g., array vs. scalar) and any date-related details. This is a modest gap for an otherwise simple data retrieval tool.

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 provides only the type and default for 'ultimos' with no description. The tool description adds the essential meaning 'nº de meses' (number of months), fully compensating for the 0% schema coverage on this single parameter.

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 explicitly identifies the resource (IPCA, official inflation) and the metric (monthly variation in %), making it distinct from sibling tools like get_igpm or get_selic. Even though the verb is only implied by the tool name, the resource and output are unmistakable.

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?

No explicit guidance is given on when to use this tool versus alternatives such as get_igpm or get_selic. Usage is implied by the specific index name, but the description does not mention exclusions or alternatives, leaving the agent to infer the appropriate context.

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