mask_sensitive_data

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

Annotations only provide destructiveHint: false. The description adds behavioral detail: replacement with [REDACTED] tags, which is not in annotations. However, it does not elaborate on reversibility, output format, or side effects, leaving some gaps. Nevertheless, it improves upon the minimal annotation.

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 two sentences, with a front-loaded directive ('Use this before...') followed by the action. Every word earns its place; no redundancy or unnecessary detail.

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 4-parameter tool with full schema descriptions and no output schema, the description sufficiently conveys what the tool does and when to use it. The redacted output is implied from the replacement behavior. Sibling context is clear.

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 coverage is 100%, so baseline is 3. The description mentions emails, phones, URLs, corresponding to the boolean parameters, but adds no new semantics beyond the schema's 'Set to true to mask...' descriptions. No additional constraints or format details are provided.

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 the tool's purpose: redacting sensitive PII (emails, phones, URLs) by replacing them with [REDACTED] tags. It uses a specific verb 'mask' matching the tool name and distinguishes from siblings (extract_pattern, validate_pattern) by focusing on redaction, not extraction or validation.

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 instructs to use this tool before sending sensitive user content to external systems, providing clear context. It implies when not to use (if not sending externally) and the siblings are for different tasks, offering implicit differentiation.

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