veredito

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

With no annotations the description carries the full burden and does well: it discloses the no-key/any-stock access model, the deliverable content (confidence flag green/yellow/red, restatement/recency/checks, citation, 25-word headline), and an explicit behavioral constraint (factual, no judgment adjectives, no recommendation). It omits error behavior, rate limits, and latency characteristics, so a 4 rather than 5.

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?

Front-loaded with the core promise ('Resumo DESCRITIVO de uma ação da B3 em seis números e três perguntas') and then organized by the three questions with parenthetical metric names; capitalization is used to segment output elements. It is dense and somewhat longer than necessary, but each clause maps to real content an agent needs.

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 single-parameter analytical tool with no output schema and no annotations, the description covers what the result contains, its constraints, and its access model well. The remaining gap is the ticker input format, which nothing else in the structured data supplies.

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?

One parameter with 0% schema coverage, so the description must compensate. 'Aberto para qualquer ação' loosely signals that the sole parameter is a B3 stock ticker, but it never specifies format, casing, or accepted variants, leaving the schema's bare 'ticker' string largely unexplained.

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 precisely what the tool returns: a descriptive summary of a B3 stock in six numbers (net margin, ROIC, net debt/EBITDA, P/L, P/VP) plus a confidence flag and a headline sentence. The verb+resource is unambiguous and the enumerated metrics make it identifiable without opening the schema. It loses a point only because it never names or contrasts with the obviously related siblings (multiplos, scores, saude).

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?

There is no when-to-use / when-not-to-use guidance and no alternative tool is named, despite many overlapping siblings (scores, multiplos, saude, desempenho). 'Aberto para qualquer ação, sem chave' establishes accessibility but not the condition that should make an agent pick this tool over the others.

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