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

Annotations already establish the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds two genuinely new facts: the tool is free of charge and the response contains counts and the latest ingestion time. It does not state refresh cadence or whether coverage is broken down per dataset, which would push this higher.

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?

Eight words in two fragments, with the substantive content ('cobertura atual do banco') front-loaded ahead of the parenthetical detail and the cost note. Nothing is padded, though the telegraphic phrasing slightly weakens readability.

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 zero-argument, read-only metadata tool with rich annotations and no output schema, the description covers what the agent needs: what is returned and that it is free. It is complete enough to call correctly, with only the exact meaning of 'cobertura' (which entities, what granularity) left implicit.

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?

The schema has zero parameters, so per the baseline this is a 4. There is nothing for the description to clarify on the input side, and the coverage statement applies to the whole call with no arguments needed.

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 names a concrete resource and its payload: 'Cobertura atual do banco (contagens e última ingestão)' tells the agent this returns database coverage counts plus the last ingestion timestamp. It is a nominal phrase with no verb, but the scope is specific enough to separate it from the financial-data siblings (precos, dividendos, screener), which all report market data rather than dataset freshness.

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?

Usage is only implied: the agent can infer this is a status/metadata probe, and 'Gratuito' signals there is no cost barrier to calling it. There is no explicit when-to-use, no when-not-to-use, and no sibling is named as the alternative for any adjacent need (e.g. metodologia or dicionario).

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