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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It reveals multiple non-obvious traits: payment wallets cannot login to the portal, access is only via API/MCP, automatic Solana wallet minting, full transaction capability including virtual bank accounts, up to 30-second processing time, and legal responsibility assumed by the human. These go far beyond a simple 'creates' and give the agent a clear mental model.

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 long but every sentence adds substantive value—scope, constraints, side effects, timing, and parameter guidance are all covered. The @param section is well-organized and front-loaded after the core purpose. Slightly verbose, but no wasted words; it earns its length.

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 the 7 parameters, no annotations, and an output schema that exists, the description is fully complete. It covers prerequisites, side effects, timing, parameter semantics, and even post-usage advice (what to save). The only missing piece is a detailed return structure, but since an output schema is present, that is not the description's responsibility.

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 description coverage is 0%, so the description must compensate. It provides detailed @param explanations for every parameter, including format requirements (secret minimum 8 chars and unique, PIN 5 digits, e164 mobile format), default behavior (secret optional with generated default), and mapping (currency_fk 7 for ZAR, 3 for USD). This is exceptional parameter documentation that fully bridges the schema gap.

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 'Creates a payment wallet' with a specific verb and resource, and then clarifies the nature of a payment wallet as a sub-wallet controlled by a sponsor. It does not explicitly differentiate from sibling tools like payment_wallet_set or automated_signup, but the description is sufficiently clear about its unique role.

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 provides prerequisites (must be created by a human KYCed wallet) and hints at when to use it (to create a sub-wallet for a sponsor), but it does not explicitly state when to use this tool versus alternatives like payment_wallet_set or automated_signup. No direct comparison or exclusion is provided.

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