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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds no behavioral detail beyond the content of the result (voices and their languages), which is useful but not a behavioral disclosure such as rate limits, authentication, or result-set volatility.

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 short sentence that wastes no words. It is concise and immediately identifies the core purpose, though it is structured as a noun phrase rather than a complete verb-led sentence.

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, read-only list tool with an output schema present, the description captures the essential information: what is being listed and what detail is included. It does not need to explain return values because the output schema exists, and the annotations cover safety.

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 tool has zero parametersainer, so there is nothing for the description to clarify about argument semantics. Baseline 4 is appropriate because no parameter information is missing and the schema coverage is effectively complete.

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 names the resource ('voice catalogue') and the key characteristic it exposes ('the language each one speaks'), making the tool's purpose understandable. It lacks an explicit verb like 'lists' or 'returns', which keeps it from a 5, but it is clearly distinct from the audio-generation and transcription siblings.

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 does not state when to use this tool versus alternatives such as speak_text or identify_speakers. There is no mention of using it to discover available voices before speaking or generating audio, so the agent receives no explicit usage routing.

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