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

Annotations already cover the read-only, idempotent, non-destructive nature of the call, so the description does not need to restate those. It does add one useful behavioral detail beyond annotations: the Scale plan requirement. However, it does not disclose other behavioral traits such as error cases or response specifics, so it adds value but not rich context.

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 two short, front-loaded sentences. The core action comes first, and the plan requirement is a necessary gate. Every word earns its place; there is no redundant or vague 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?

For a two-parameter read operation with full schema documentation and a rich output schema, the description plus input schema gives an agent everything needed to invoke it correctly. The plan prerequisite is present, and the safety profile is already captured by annotations.

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?

Schema description coverage is 100%: both courseId and translationId are already documented in the input schema, including the useful note that translationId is not a locale code. The description contributes no additional parameter-level semantics, so the 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 states a specific action verb ('Fetches'), a concrete resource ('one locale's translated fields'), and the singular scope. This clearly distinguishes it from sibling tools like list_translations, and it is not merely a restatement of the name.

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 implies when to use this tool: to fetch a single locale's translated fields. It also adds a meaningful prerequisite ('Scale plan or higher'), but it does not explicitly name alternatives such as list_translations for fetching all locales, nor does it state when not to use this tool.

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