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

Goes well beyond the annotations with details the agent could not otherwise know: no logging/storage of submitted text, $0.02 per-call x402 pricing in USDC on Base, bad input is not charged, and redacted text returned only when redact is true. The readOnly/non-destructive safety profile is consistent with annotations and the added privacy and billing behavior is exactly the kind of context a caller needs.

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?

Front-loaded with the pattern list, which is good, but later sentences are repetitive boilerplate: 'USDC on Base' appears three times, plus a warranty disclaimer and a terms URL that add bulk without aiding tool selection. Roughly a third of the text could be trimmed.

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, and the description compensates by describing the return shape (findings with type and offsets, plus redacted text conditionally), the input encoding, the privacy posture, and the billing model. An agent has everything needed to call this 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 coverage is 100%, so text and redact are already fully documented in the schema. The description's 'POST JSON {text, redact?}' and the redact-true behavior restate the schema rather than adding syntax, limits, or format guidance. 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?

States a specific verb+resource ('scan of supplied text') and enumerates exactly what is detected: email, phone, SSN, Luhn-checked cards, mod-97 IBANs, IPs, private-key shapes, BIP-39 phrases, API-key shapes. This is clearly distinguishable from nearby sibling tools such as extract, search, or http, which do not perform pattern classification.

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?

Gives clear framing for use: 'best-effort only, not a compliance assessment' and 'Informational only, no warranty', which tells the agent when results are and aren't authoritative. It does not explicitly name an alternative tool (e.g., extract) or state when not to call it, so it stops short of full when/when-not routing.

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