elevenlabs_list_voices

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

With no annotations provided, the description bears full responsibility for behavioral disclosure. It fails to mention read-only nature, pagination, rate limits, authentication needs (though api_key is in schema), or any side effects. For a tool with no annotation support, this is a significant omission.

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 of only five words, which is concise and front-loaded. However, it sacrifices necessary detail for brevity. It earns its place but could be improved with minimal additional information.

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?

Given the absence of an output schema, the description should clarify the return format (e.g., voice IDs, names). It does not, leaving the agent uncertain about what the tool returns. With many sibling tools, more context is needed to set expectations.

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 coverage is 0%, and the description adds no meaning about the single required parameter (api_key). It does not explain its purpose, how to obtain it, or its format. The agent must guess its usage, which is insufficient for correct invocation.

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 'List all available voices in ElevenLabs' uses a specific verb ('List') and clearly identifies the resource ('all available voices'). It effectively distinguishes this tool from siblings like elevenlabs_get_voice (single voice) and elevenlabs_text_to_speech (generates speech), 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?

No guidance is provided on when to use this tool vs alternatives. There is no mention of prerequisites (e.g., need for an API key), context for use, or exclusions (e.g., if no voices are available). This leaves the agent without sufficient information to decide on using this tool.

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