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

The description discloses that the tool lists 90+ languages and provides localized names based on the display_language parameter. Annotations already indicate readOnly, idempotent, and non-destructive, but the description adds context about the output scope.

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 extremely concise with two sentences, no fluff, and front-loads the key purpose.

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 simple list tool with a single optional parameter and an output schema, the description is complete. It covers the purpose, the optional localization feature, and the approximate count of languages.

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 already has a clear description for display_language. The tool description adds little beyond what the schema provides, but since schema coverage is 100%, a baseline of 3 is appropriate.

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 lists all 90+ supported translation languages with localized names, and the name and title reinforce this. It is distinct from siblings like translate.text.translate and translate.text.detect.

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 indicates when to use it (when you need the list of languages) and mentions the optional display_language parameter. It does not explicitly state when not to use it, but for a simple list tool this is sufficient.

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