cambio__listar_moedas

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

The tool has no annotations, but the description transparently states it lists all moedas with 'simbolo' and 'nome' fields. It implies a read-only operation with no side effects, which is sufficient for a simple listing.

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?

Two concise sentences with no wasted words. The description is front-loaded with the action and clearly structured.

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?

Given no parameters, an output schema exists, and the tool is simple, the description fully covers what the agent needs to know: what it does and what it returns.

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?

No parameters exist, so baseline is 4. The description correctly adds meaning by naming the output fields (simbolo, nome), which compensates for the lack of input schema details.

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 states it lists all available currencies ('moedas') for exchange rate queries, using a specific verb ('Lista') and resource ('moedas'). It implicitly distinguishes from the sibling tool 'cambio__consultar_cotacao' which provides quotes.

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 guidance on when to use this tool vs. alternatives. It could mention that it should be called before consulting exchange rates (cambio__consultar_cotacao) to obtain available currency symbols.

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