List Voices

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

The description adds no behavioral information beyond what the annotations already declare (readOnlyHint, openWorldHint, idempotentHint, destructiveHint=false). It does not mention authentication, rate limits, output structure, or any side effects, and unlike the get_calls example, it adds no extra operational constraints. This is a minimal disclosure that relies entirely on 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 a single sentence that directly states the action and object with no redundant words. It is front-loaded with the verb 'List' and efficiently conveys the tool's function within eight words.

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 parameterless, read-only list operation, the description adequately states the tool's purpose. The annotations cover safety and idempotency, and the absence of an output schema is less critical for a simple list operation. However, the description could be slightly more explicit about what the returned voice configuration contains, so it's not a perfect 5.

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 parameters, and the schema is an empty object. Per the rubric, a zero-parameter tool gets a baseline of 4. The description doesn't need to explain parameters, and it doesn't attempt to add semantics for nonexistent inputs.

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 uses a specific verb 'List' and identifies the resource as 'available ElevenLabs voices configuration', clearly distinguishing it from the many other list tools in the sibling list. It adds provider context (ElevenLabs) beyond the name/title, making the purpose unambiguous.

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 used when the agent needs to retrieve available ElevenLabs voice settings, but it provides no explicit guidance on when to prefer it over alternatives or any exclusions. Since the tool is a unique read-only list operation with no parameters, the usage context is reasonably inferable, but the description itself does not articulate it.

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