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

Annotations already cover the safety profile (readOnly, non-destructive, open-world), and the description adds real value beyond them: it discloses the detection scope (unauthorized approvals, replay attacks) and, unusually, the cost (0.02 USDC on Base or Solana), which an agent must know before invoking a paid tool. It does not mention latency or rate limits, keeping it short of a 5.

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 sentences, purpose first, commercial constraint second. No filler, nothing buried, and the enumeration of supported payload types is packed into the opening clause.

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?

An output schema exists, so return values need no explanation, and annotations cover safety. The description supplies scope, supported formats, and payment terms — enough for a confident call. The remaining gap is sibling disambiguation against auditEip712Signature.

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?

One parameter with 0% schema coverage, so the description must carry weight. Naming Permit/Permit2/transferWithAuthorization tells the agent which typed-data dialects are accepted, which is genuinely useful, but it never explains the typed_data object's required members (domain, types, primaryType, message) or their expected shapes.

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 (audits) and resource (EIP-712/EIP-3009 typed-data signature payloads) and enumerates the concrete formats handled (Permit, Permit2, transferWithAuthorization). It does not, however, distinguish itself from the near-identically named sibling auditEip712Signature, so an agent must guess which one applies.

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 phrase 'to prevent unauthorized token approvals and replay attacks' implies the usage context, but there is no explicit when-to-use vs when-not-to-use guidance and no pointer to auditEip712Signature as the alternative for the simpler case. Usage is inferable but not directed.

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