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

With no annotations provided, the description carries the full transparency burden. It discloses the data included and the authentication requirement (chave_api for non-MXRF11 funds). It does not mention rate limits or explicitly state read-only behavior, but the listed content and key requirement provide substantial transparency for a data-retrieval tool.

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 concise and well-structured: two sentences that start with a clear purpose and then list specific data items, followed by a crucial access note. Every clause adds value with no redundancy.

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 the tool has only two parameters, no output schema, and no annotations, the description provides a solid overview: purpose, data contents, and access conditions. It lacks explicit error handling or output format details, and does not distinguish itself from overlapping sibling tools, leaving some gaps, but overall it is fairly complete.

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 coverage is 0%, so the description must compensate. It does so by explaining that the tool requires a ticker (implicitly via MXRF11 example) and that chave_api is required for funds other than MXRF11. This gives meaningful context to both parameters beyond the bare 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 clearly states the tool provides details of a real estate fund (FII) and enumerates specific data points (cadastro, último informe, historical P/VP series, current 12m DY, and last dividends paid). This makes the purpose specific and valuable, but it does not explicitly differentiate from sibling tools like fiis_ranking or dividendos.

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 implies usage by indicating it is for individual FII details and explains that only MXRF11 is open for free testing while others require an API key. However, it does not provide explicit when-to-use or when-not-to-use guidance compared to alternatives, such as directing users to fiis_ranking for rankings or dividendos for broader dividend queries.

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