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

Goes well beyond the annotations by explaining irreversibility of payout_address, the Central Bank requirement for CPF/CNPJ, idempotency via external_id, and detailed error semantics. It adds operational warnings about confirming the full address and never taking it from untrusted sources, which is exactly the context an agent needs.

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?

Long but every section earns its place given the irreversible financial risk. Information is front-loaded with the API key requirement and central function, then organized into parameter safety, usage cautions, and error handling. The structure makes the density navigable.

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?

Despite no output schema, the description tells the agent what is returned, what to do before calling, how to handle each failure class, and which compliance statements to avoid. For a six-parameter financial tool, this is complete enough for correct selection and invocation.

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?

Adds substantial meaning beyond the schema: amount_cents is explicitly integer cents with an example, payout_address must come from the user/configuration and be confirmed in full, payer_tax_number must be the real payer per Central Bank rules, and external_id is for retry idempotency. This compensates richly for any schema-only parameters.

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 verb, resource, and outcome: it creates a PIX charge, returns a QR code and copy-and-paste string, and delivers crypto on payment. The title and description make it unmistakable from siblings like lunium_get_pix_charge or lunium_verify_pix_payment.

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?

Explicitly says to call lunium_check_payer_limit first, warns against creating a charge while a previous one for the same intent is pending, and gives error-specific retry/stop guidance (corrigir, esperar, repetir). It also states what not to do, such as describing the flow as anonymous or KYC-free.

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