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

Beyond the readOnly/openWorld/idempotent annotations, the description reveals critical behaviors: all four receipt fields arrive together, URLs must never be hand-constructed, polling too fast consumes the request budget and yields quota errors, and receipt_pdf_url contains PII that must not be fetched or forwarded. It also states there is no cancel and that pending states are normal outside Polygon. No annotation contradiction exists.

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 description is dense but every sentence earns its place: return fields, usage ordering, polling limits, PII handling, exclusions, and error semantics are each covered in a structured, front-loaded way. It is long because the tool has nuanced failure modes and privacy constraints, not because of padding.

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 single-parameter read-only polling tool with no output schema, the description is complete: it names all returned values, explains their purpose, gives the prerequisite workflow, sets polling expectations, covers quota errors, addresses PII handling, and routes the agent away from inappropriate uses. An agent has everything needed to call it correctly.

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 already covers the single parameter fully, specifying that cashout_id is the order id from lunium_quote_crypto_sale and not the external_id or E2E. The description reinforces the context of the parameter but adds little semantic meaning beyond the schema, so the high-coverage baseline of 3 is appropriate.

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 uses a specific verb and resource: it returns the current state of a crypto sale and the settled receipt fields (pix_e2e, receipt_url, receipt_pdf_url, verify_url). It also distinguishes itself from lunium_verify_pix_payment and references the preceding lunium_confirm_crypto_sale, making the tool's role unambiguous.

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?

The description explicitly states when to call the tool (after confirming the sale and sending crypto to the deposit address), how often to poll (10-15 seconds), when not to use it (payments outside Lunium), and how to interpret error codes (acao=repetir, esperar, corrigir). It also warns against retrying the same id on not-found, providing a clear decision path.

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