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

Annotations already convey non-read-only and idempotent=false, but the description adds meaningful behavior: the nonce is single-use, not a credential, and tenant_code must not be logged. The upfront 'Public' declaration also matches the openWorldHint 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 uses four tight sentences, each earning its place: purpose, usage flow, authorization pattern, and security warnings. No filler, and the core purpose is front-loaded.

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 simple one-parameter tool with no output schema, the description covers purpose, the sign-in flow, optionality of tenant_code, and sensitive-data handling. It does omit response format or expiry behavior, but those are minor for issuing a nonce.

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 only describes body as a JSON object with wallet_address and tenant_code, but the description adds that wallet_address is the target and tenant_code is optional scoping. It also provides a security-relevant warning about tenant_code. It stops short of specifying the wallet_address format.

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 states a specific action: 'issue a single-use SIWE nonce for wallet_address' and clearly ties it to the EIP-4361 wallet sign-in flow. It also distinguishes itself from sibling auth tools by calling out the dedicated SIWE agent auth pattern.

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 gives a clear usage flow: embed the nonce in an EIP-4361 message, sign it, then call login with provider: siwe. It explains this is how an agent signs in without raw HTTP, but it does not explicitly enumerate when to avoid sibling tools like getAuthConfig or requestOtp.

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