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

With no annotations provided, the description carries the full behavioral disclosure burden and handles it well: it discloses the data scope (2010–today), the indicator set, the FII exclusion behavior, the bank/insurer limitation (no ROIC/EBITDA due to their chart of accounts), and the API-key requirement. It stops short of describing the return format or what 'flags de qualidade' mean, but the core behavioral traits are transparent.

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?

Three short paragraphs, each with a distinct job: what the tool returns, exclusions and alternative routing, and auth/pricing. Every sentence earns its place and the core purpose is front-loaded in the first sentence. No filler or repetition.

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 2-parameter tool with no annotations and no output schema, the description is nearly complete: it covers purpose, valid inputs, exclusions, alternatives, and auth requirements. The only minor gaps are the undefined 'flags de qualidade' and the lack of a return-structure sketch, though the enumerated metric list already gives an agent a solid expectation of the response.

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%, so the description fully compensates: it defines the valid `ticker` space (B3 stocks only, not FIIs ending in 11, banks/insurers allowed with caveats) and specifies when `chave_api` is required (all tickers except WEGE3) and which tiers work (free or Pro). This is exactly the parameter-level meaning the schema fails to provide.

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 a specific verb-resource relationship: it provides an annual series (2010–today) of ROIC, ROE, margins, growth, and net debt/EBITDA for a single B3 stock, with quality flags. It distinguishes itself from siblings by explicitly excluding FII tickers and routing them to `fii`, and by noting banks/insurers are included with limitations.

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 explicit when-to-use/when-not-to-use guidance: FII tickers ending in 11 (e.g., MXRF11) must NOT be queried here and should use `fii` instead, with the rationale that FIIs have P/VP, DY, and vacancy rather than ROIC/EBITDA. It also states the prerequisite that WEGE3 is free while all other tickers require chave_api.

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