payment_transfer

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

With no annotations, the description carries the full burden and meaningfully discloses non-obvious behavior: the sender pays a trust-level-based fee, the operation is idempotent per order_id, and to_user_id/to_username must match. It does not cover error/reversal behavior, but core side effects are transparent.

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 dense sentences with no filler. The primary action is front-loaded, and the constraints are packed efficiently. Every clause adds value: direction, official API, identity consistency, fee, and idempotency.

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 no annotations and no output schema, the description covers the essential operation, constraints, fee, and idempotency, which is a solid minimum. However, it omits return/error behavior, auth expectations, and what happens if the identity constraint is violated, so it is not fully complete for a financial mutation tool.

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 only 25% (order_id documented), so the description must compensate. It adds that to_user_id and to_username must refer to the same user, and implies amount is in energy points. But it leaves to_user_id/to_username formats and amount bounds mostly to inference, so gaps remain.

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: 'Transfer energy points from the payment-app owner to a user' via the 'official Payment API.' It clearly differentiates this from siblings like payment_create and payment_query, which describe different operations.

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 intended usage is implied: use this to transfer energy points from the owner to a user. However, it does not explicitly contrast with payment_create/payment_query or state when not to use it. The mention of 'official Payment API' gives context but not clear alternative routing.

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