ai_usage

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It indicates a read-only operation ('Get... usage') and specifies the data returned (used words, quota, remaining balance). However, it does not mention authentication requirements, rate limits, or any potential side effects. For a simple query, this is adequate but not thorough.

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?

The description is a single, well-structured sentence of 15 words. It front-loads the verb and resource, immediately conveying the tool's function. Every word adds value, and there is no unnecessary repetition or filler.

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 the tool's simplicity (one required parameter, no output schema, no nested objects), the description adequately covers what the tool does and what it returns. It mentions the billing period and the three metrics (words, quota, balance). While it could specify the return format (e.g., JSON structure), the current text is sufficient for an agent to understand the expected outcome.

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 input schema has 100% coverage: the sole parameter 'project_id' has a description ('The project ID'). The tool description adds no additional meaning about the parameter, such as its format, allowed values, or how to obtain it. With full schema coverage, the description does not need to compensate, but it could offer helpful context.

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 clearly states the tool's purpose: 'Get AI translation usage for the current billing period'. It specifies the verb ('Get'), the resource ('AI translation usage'), and the scope ('current billing period'). It also lists the returned data (used words, quota, remaining balance). This distinguishes it from sibling tools like 'ai_translate' (performs translation) and 'get_usage' (likely more general).

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 description provides no explicit guidance on when to use this tool or when to choose an alternative. It does not mention prerequisites, common use cases, or situations where other tools (e.g., 'billing_history', 'allowance_status') would be more appropriate. The context is implied but not stated.

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