List Coupons

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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds no behavioral context beyond that: no pagination, no filtering, no indication of how many coupons exist or what an access code represents. It does not contradict the annotations, but it contributes nothing.

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?

A single front-loaded phrase with zero waste, which is appropriately terse for a zero-parameter list call. It reads as under-specification rather than deliberate conciseness, though, so it does not reach the top of the range.

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 an output schema present and no parameters, the description only needs to say what is listed, and it roughly does. The slash-joined dual noun leaves ambiguity about whether these are one resource or two, which is a modest but real gap for a tool with no other documentation.

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 takes zero parameters, so the schema-description baseline of 4 applies. There is no parameter surface for the description to clarify or obscure.

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 verb (列出) and a resource (上网码/优惠券), so the basic operation is identifiable. However, it conflates two distinct entities with a slash and gives no scope, contents, or distinction from siblings like list_packages or list_pppoe_accounts. Vague enough that an agent cannot be confident what a 'coupon' or 'internet access code' is in this system.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives among the many sibling list_* tools. The name implies a simple enumeration, so usage is weakly inferable, but the description adds nothing to that inference.

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