get_poupanca

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the output metric and unit; it does not describe whether the result is the latest value, a historical series, what the 'ultimos' parameter changes, or what the response looks like.

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 very short, front-loaded, and contains no filler words. It conveys the core metric in a compact form, though the compactness comes at the cost of missing important detail.

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 tool with one undocumented parameter and no output schema or annotations, the description is not complete enough. An agent can invoke it with defaults, but cannot reliably understand how to request historical values or interpret the result beyond 'monthly percentage'.

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 0%, and the description does not mention the 'ultimos' parameter at all. The schema only shows it is an optional integer with a default of 1, so the agent cannot learn what the parameter means from either source.

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 identifies the resource (poupança) and the metric (monthly yield in %), so an agent can infer what the tool returns and distinguish it from siblings like get_selic or get_cdi. However, it is a noun phrase rather than an explicit verb+resource statement, and it does not explicitly differentiate it from the sibling tools.

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 no guidance about when to use this tool instead of alternatives such as get_selic, get_cdi, or get_ipca. There is no mention of context, prerequisites, or exclusions, so an agent must rely entirely on domain knowledge.

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