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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered by structured data. The description adds that the result includes textoMascarado and naoMedido, which is useful return-shape context in the absence of an output schema, but it never explains what 'naoMedido' means or how masking is applied.

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 short, front-loaded sentences with no filler. Some telegraphic tokens ('names A–J', 'naoMedido') cost readability but not word count, so it stays efficient.

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 one-parameter, no-output-schema tool with annotations, the essentials are mostly covered, and the description does disclose the two returned fields. However, undefined domain terms (naoMedido, 'names A–J') and the lack of any sibling disambiguation leave an agent guessing at scope.

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?

There is a single parameter with 100% schema description coverage ('Text to scan'), so the schema carries the semantics. The description adds nothing about the text parameter (size limits, encoding, whether it accepts multi-line or JSON). Baseline 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?

States a specific verb+resource ('PII scan') and enumerates the entity types it detects (CPF, CNPJ, RG, MASP, EMAIL, names A–J), which is concrete. It does not differentiate itself from the siblings guard_check_safe and guard_inspect, so an agent cannot tell from the description alone which of the three to pick.

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 word 'Quick' hints at a faster/lighter alternative to something, but no when-to-use condition, prerequisite, or named alternative is given. With two sibling guard tools, the absence of routing guidance is a real gap.

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