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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered structurally. The description adds the useful behavioral fact that this returns access state and a recovery code without triggering a new purchase. Beyond that, it says nothing about permissions, failure cases, or invocation cost.

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?

A single compact sentence with no filler, and the key constraint ('sem nova compra') is front-loaded. It is efficient, though it is arguably too terse to be self-explanatory.

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?

There is no output schema, so the description should clarify what comes back; it gestures at 'estado do acesso' and the recovery code, which roughly covers the return. Given only two fully documented parameters and an annotated read operation, this is adequate but leaves the access code's role (input vs. output) ambiguous.

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 description coverage is 100%, with both id ('Documento comprado') and acesso_codigo ('Código privado de acesso') documented in the schema. The description adds no parameter-level detail beyond that, 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 description names the resource (access status and private recovery code) and an implicit retrieval verb, but it never states the action plainly, so the agent must infer 'get/fetch' from the name. It hints at sibling differentiation via 'sem nova compra' (no new purchase), distinguishing it from compra/meus_compras, but not crisply.

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?

'Sem nova compra' implies the retrieval scenario that selects this tool over a purchase flow, which is a light usage cue. However, there is no explicit when-to-use, no prerequisites, and no naming of an alternative sibling such as documento, documento_leitura, or meus_compras.

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