List PII/secret detectors and pricing (free)

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

Annotations already establish readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description still adds real value beyond them by disclosing that this is static local data with no network and no token/cost, plus that paid coverage is gated behind the Actor — context annotations do not convey.

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 labeled WHAT/WHEN/WHEN NOT/COST/RETURNS/EXAMPLE structure is front-loaded and scannable, with each section carrying distinct information. Slightly verbose in aggregate, but no section is filler.

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?

With an output schema present, return-value detail is not strictly required, yet the RETURNS line and EXAMPLE still orient the agent. Cost, coverage tiers, and routing to alternatives are all covered, so nothing an agent needs to call this correctly is missing.

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 tool takes zero parameters, so the baseline is 4; there is no input schema semantics for the description to add. It does clarify what entityTypes the output enumerates, which is useful framing though not strictly a parameter concern.

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 WHAT section names a specific resource (catalog of PII/secret entity types) and precisely scopes it: which run locally vs only in the paid Actor, redaction styles, and pricing. An agent can immediately distinguish this from pii_scan_text and pii_redact_text without opening any schema.

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?

Explicit WHEN (before scanning/redacting to pick entityTypes, or to explain coverage and costs) and WHEN NOT (not to scan or redact), naming the exact sibling tools to use instead. Nothing is left to inference.

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