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

With no annotations present, the description carries the full burden and does so well: it discloses the return value (masked destination on file plus the masked address the link was sent to), the security constraint (form URL never shown in chat, link goes only to the email on file), and an explicit behavioral instruction (never ask the user to type the number or wallet address). This is unusually rich disclosure.

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 action and usage trigger are front-loaded, and nearly every sentence carries operational value (destination types, return shape, security behavior). It is long and slightly over-explained in places, but no sentence is pure filler.

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?

Although there is no output schema, the description explicitly states what is returned (the masked destination and the masked email address), and it covers the security constraints and user-facing instructions an agent needs. Nothing material for correct invocation is missing.

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 description coverage is 100% and the single customerKey parameter is already documented in the schema, including the 'omit when connected through a personal token URL' guidance. The description adds no parameter-level detail, so 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?

The description states a specific verb and resource: it emails a link to the payout-registration form for a GYOTAK referrer's commission destination. It even enumerates the two supported destination types (Thai PromptPay QR, USDC on Base / USDM on Cardano), so an agent knows exactly what this tool accomplishes.

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?

It gives an explicit trigger: 'Call this when the user wants to register, see, or change their payout destination.' That covers the main invocation paths clearly. It does not name when-not-to-use or a competing sibling, but no sibling overlaps this payout-registration purpose.

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