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

Annotations only declare readOnly=false, idempotent=false, and destructive=false. The description adds substantial behavioral context: USDC confirmation on Base safe block versus L1 finality, 30-minute send window, 24-hour observation, late/wrong-chain/failed-extraction cases requiring support, wallet fees, same X-Cobranca preserving charge/address, paid GET returning access code/cookie, and dev simulated payments being invalid.

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?

It is front-loaded with the purpose and packs many operational constraints into dense sentences. The length is justified by payment complexity, though the structure is somewhat stream-of-consciousness and a few clauses could be tightened.

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?

No output schema exists, but the description covers important follow-up context: paid GET returns acesso.codigo and a cookie, and linking to an account uses POST /api/documento/:id/vincular. It still does not fully specify the immediate return payload of criar_cobranca itself.

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 the baseline would be 3. The description adds workflow meaning beyond the schema: cotacao must come from estado_geracao and be checked/submitted, and cobranca_token must be generated and conserved by the client before creation.

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?

States a specific action and resource: it reserves a USDC/Base address for paying US$0.02 per page without a browser wallet. The purpose is clear, but it does not explicitly distinguish itself from sibling tools such as estado_cobranca or estado_geracao.

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?

Provides concrete workflow conditions: check cotacao first, preserve cobranca_token, do not generate before real confirmation, consult GET /geracao and submit cotacao, and send within 30 minutes. It lacks explicit when-not guidance or named sibling alternatives, but the prerequisites and timing are unusually well covered.

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