Delivery slots

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: it reads slots for the account's address, reports fee/free_from/selected-slot details, and cannot modify the selected slot.

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?

Three short sentences, front-loaded with the core purpose, followed by important caveats about merchant/farm-direct separation and the inability to set a slot. No sentence is wasted.

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?

With zero input parameters, rich annotations, and an output schema, the description provides everything needed: what is returned, the account-address scope, separation of merchant/farm-direct items, and the checkout-only limitation. No important agent-facing context 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?

The tool has zero parameters, so the baseline is 4. The description correctly implies it uses the account's address implicitly rather than requiring input parameters.

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 names a specific resource (HKTVmall delivery slots), the account-address scope, and the returned details including fee, free_from, and any selected slot. It also distinguishes merchant and farm-direct item slots, so an agent can understand exactly what data this tool provides.

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 clearly states a key limitation: the person picks the slot at checkout and this tool cannot set one. That gives useful when-not-to-use guidance, though it does not explicitly name a sibling tool as the alternative for checkout actions.

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