translation options

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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, and the description restates the no-side-effect/no-cost profile while adding real context beyond the annotations: the previews tools only exist when previewAvailable is true, and codes follow es / pt-BR / zh-TW shapes. It doesn't describe the response shape in detail, but that is largely covered by the output schema.

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?

Front-loaded with what is returned, then usage, then the anti-use case, then a clarifying format note. Dense but nearly every sentence carries information; the 'Takes no input ... creates nothing and costs nothing' clause is somewhat redundant with the readOnly annotation.

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?

For a zero-parameter lookup with an output schema and full annotations, nothing an agent needs is missing: it knows what is returned, what the codes look like, which siblings to feed them into, and which tools to avoid for pricing.

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?

There are zero input parameters, so the baseline is 4; the description correctly says it takes no input. It adds useful semantics about the returned values (sourceLanguages includes 'auto' for detection) and the code format, though the output schema already carries much of that.

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?

States a specific verb and resource: it lists the language codes accepted for translation (targetLanguages, sourceLanguages with 'auto') plus the previewAvailable flag. That is distinguishable from every sibling, including the create/estimate tools it names.

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?

Gives explicit when-to-use ('pick a valid targetLang or sourceLang for dubbing_create or translation-previews_create'), a concrete edge case (translation-previews_create takes free text, so check codes here first), and an explicit when-not ('Not for prices: use generations_estimate-cost or translation-previews_estimate').

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