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

Annotations already declare readOnly/idempotent/non-destructive, yet the description adds substantial behavioral context beyond them: no charge, per-credential franchise bounded by the earlier of 30 days or pilot end, dedup (re-reading the same document consumes no unit), and premium credential header requirements. This is genuinely useful operational detail, though it could state the return shape more clearly.

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 purpose is front-loaded, but the description then crams franchise limits, dedup rules, payment warnings, premium headers, and pilot budget into one dense block, with mild redundancy ('Não cobra' vs 'Não envie pagamento'). Several sentences earn their place; the structure does not.

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 read-only, no-output-schema tool, the description covers the key things an agent needs: polling trigger, billing/franchise behavior, dedup, and premium credential headers. It is nearly complete, only lacking any note on pagination across pages or response shape.

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 100%, so both parameters (id, agent_pass) are already fully documented in the schema. The description reinforces agent_pass as a persistent credential but adds no syntax, format, or edge-case detail beyond the schema, so the baseline 3 applies.

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 opening sentence gives a concrete verb+resource: retrieve básico reading text per page with source hash, and it explicitly contrasts with premium ('Básico não abre conteúdo premium'). An agent can distinguish it from avaliacao_premium, though the rest of the text is dominated by billing/pilot prose that dilutes the core purpose.

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?

It implies this is the follow-up poll tool ('Acompanhe a leitura básica após retry_after_s') and notes basic won't open premium content, but it never names or routes against the sibling avaliacao_basico, which is likely the initiation counterpart. Usage is implied rather than stated.

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