guardrails_scan_pii

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

No annotations are present, so the description carries the burden. It discloses that scanning costs 1 TNC (a behavioral trait) and detects specific PII types. However, it does not describe output format, error behavior, or whether it is read-only or mutable. The output schema may cover return values, but behavioral aspects like idempotency are missing.

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 a single sentence that is concise and front-loaded, stating the purpose immediately. No filler or redundant information.

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 having an output schema that may detail return values, the description lacks usage guidelines, parameter semantics, and behavioral context like prerequisites or failure modes. Given the simplicity (one parameter) and existence of siblings, more detail is needed for an agent to use 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?

Schema description coverage is 0%, and the description does not explain the 'text' parameter beyond implying it is the input text. No additional meaning or constraints are provided, leaving the agent to infer its role.

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 clearly states 'Detect PII' and lists specific PII types (emails, phones, CPF, CNPJ, credit cards, SSN), providing a specific verb and resource. It distinguishes from sibling tools like guardrails_scan_injection and guardrails_scan_secrets by focusing on PII detection.

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?

No guidance is given on when to use this tool versus alternatives (e.g., guardrails_check, guardrails_scan_secrets). The description mentions cost but does not explain contexts where PII scanning is appropriate or not.

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