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

With no annotations, the description carries the full burden. It discloses the operation (listing), the exact scope (all 13 paid skills), and an operational detail (0.05 yuan per call, Alipay A2M metered billing). It does not explicitly say the call is read-only, but '列出' makes that reasonably clear.

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 sentence that front-loads the action, then gives specifics, then the purpose. Every clause earns its place, and there is no filler or redundant phrasing.

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?

This is a simple parameterless catalog; the output schema covers return structure, and the description supplies scope, pricing, billing model, and purpose. Nothing needed 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?

The tool has zero parameters, so schema coverage is trivially 100% and there is nothing for the description to add. This matches the stated baseline for 0-parameter tools.

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 the exact resource (all 13 paid skills) and the verb (列出/list), and states its purpose (discovering available capabilities). It clearly stands apart from the sibling skill tools, which are individual capabilities rather than a catalog.

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 phrase '用于发现可用能力' gives clear context for when to call this tool: before selecting among the available skills. It does not explicitly list exclusions or alternatives, but for a catalog tool that purpose statement is sufficient guidance.

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