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

With no annotations provided, the description carries the burden of behavioral disclosure. It reveals a key security posture ('FlexYield never holds keys'), explains what operations are performed (parses fields, checks signature and expiry), and notes the boundary that domain/nonce policy is left to the caller. It does not describe error or invalid-signature behavior, which would strengthen it further, but it provides meaningful behavioral context.

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 dense but well-organized sentence. It groups related information in parentheses and separates the two modes clearly. It is not bloated, though breaking it into two sentences would slightly improve scannability for an agent parsing it quickly.

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?

Given there is no output schema, the description needs to convey the verification result contract. It explains what inputs are checked and the security policy, but it does not tell the agent what the tool returns on success versus failure (e.g., boolean, parsed fields, or error). That missing piece prevents the description from being fully self-sufficient for correct invocation and interpretation.

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 schema already provides 100% coverage with descriptions for all four parameters, so the baseline is 3. The description adds valuable mode-specific semantics: it ties 'message' and 'signature' to their exact formats in each mode, clarifies 'address' as an optional expected signer for personal mode, and explains that SIWE mode parses embedded fields from the message text. This goes beyond the bare schema hints.

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 opens with a specific verb ('Verify') and identifies two concrete resource types (EIP-191 personal_sign and SIWE/EIP-4361). It clearly distinguishes the two modes ('personal' vs 'siwe') and what each validates, making it immediately identifiable among the large sibling tool list that contains no other verification tool.

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 states the exact conditions for each mode: personal mode with message + 65-byte signature and optional address, siwe mode with exact message text and signature. The closing 'Recovery only' clarifies when verification is appropriate. It does not name alternative tools explicitly, but the mode breakdown serves as practical usage guidance.

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