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

With no annotations, the description must carry the full behavioral load. It implicitly signals a read-only quota inspection by listing only observational fields (remaining count, rate limit, today's usage, status), which is helpful, but it never states that the call has no side effects, whether it consumes quota, or what auth or key scope is required.

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, front-loaded with the verb, that lists the returned data points without padding or repetition. Every element earns its place and nothing 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?

The tool is simple: no parameters and an output schema that already documents the return shape, so the description need not explain return values. It is nearly complete, with only the implicit auth context and side-effect profile left unstated.

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 there is nothing for the description to disambiguate; the baseline for a parameterless tool applies. The description adds value by naming the implicit 'current API Key' subject that the empty schema cannot express.

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 (查询) applied to a specific resource (the current API Key's quota) and enumerates exactly what is returned: remaining calls, per-minute rate limit, today's usage, and status. It does not explicitly name the siblings, but parse_video and redeem_code are unrelated domains, so the distinction is obvious from the resource alone.

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?

Phrasing like '当前 API Key' implies that the tool reads the caller's own quota, and the field list implies a pre-flight check before heavy usage. However, there is no explicit statement of when to call it, no prerequisites, and no guidance on alternatives or frequency of use.

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