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

With no annotations, the description carries the full burden. It does disclose the important behavioral fact that this creates an invoice whose payment happens outside the tool, and that a separate activation call is required — useful sequencing information. However, it says nothing about expiry of the invoice itself, whether repeated calls create duplicate invoices, or any auth/rate constraints.

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?

Two sentences, zero waste, with the generative action stated first and the required follow-up step second. Nothing needs trimming or reordering.

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 parameterless tool with no output schema, the description should explain what the caller receives back — the invoice and, critically, the id needed for the next step. It only implies this indirectly via 'chame ativar_acesso com o id', and omits the external payment mechanics and pass pricing/expiry, leaving a meaningful gap for a purchase flow.

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 tool takes zero parameters, so the baseline is 4 and there is genuinely no parameter meaning to add. The description's only parameter-adjacent content is the reference to passing 'o id' to ativar_acesso, which is about a different tool's input rather than this one's.

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 specific verb and resource — 'Gera uma fatura Lightning' for a 'passe de 24 horas às ferramentas pagas' — and explicitly distinguishes itself from the sibling ativar_acesso by positioning this as the step before it. An agent can tell what the tool produces without opening any schema.

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 gives a clear trigger condition (acquiring a 24-hour pass to paid tools) and a two-step workflow: pay the invoice, then call ativar_acesso with the id. It does not state when this should NOT be used (e.g., if an access pass is already active, or how to check that), so it falls short of explicit exclusions.

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