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

Annotations already provide readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the agent knows it's safe. The description adds that the catalog is 'curated' and 'credential-free', and points to a REST endpoint, which helps set expectations of the data source. However, it does not describe the output format beyond listing fields, though an output schema exists. The added context justifies a 3, but not higher because the critical behavioral cues are already in annotations.

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 sentences with zero fluff. It is front-loaded with the action and resource, followed by a useful note about the REST endpoint. Every word earns its place.

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 filterable list tool, the description, combined with the input schema and annotations, is complete. It mentions the purpose (configuring agent voices), the output fields, and the credential-free nature. The output schema covers return values. Nothing is obviously missing for an agent to invoke it correctly.

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% description coverage, with each parameter described as a filter by gender, language, or provider. The description does not add any additional meaning beyond what the schema provides. Per the rubric, with high coverage, the baseline is 3, and the description doesn't elevate it.

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 a curated voice catalog with specific fields (id, display name, accent, language, gender, sample URL) and mentions it mirrors the REST endpoint GET /api/v1/voices. This is a specific verb (list) and resource (voice catalog), distinguishing it from many sibling list_* tools. The inclusion of 'credential-free' is a helpful qualifier.

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 the tool is for configuring agent voicesaine, and indicates a REST endpoint. It doesn't explicitly name alternatives or state when not to use it, but the purpose is clear enough. The description's note that it is 'credential-free' could suggest it should be used when no credentials are required, though this is implicit. Since there are no sibling voice-related tools, this is acceptable.

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