Generate speech (TTS)

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

Despite having no annotations, the description discloses key behavioral traits: it uses the external ElevenLabs service, returns an MP3 URL, and incurs costs per 1,000 characters. It omits latency, error handling, and authentication details, but covers the most operationally relevant aspects for a simple TTS tool.

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?

Three short sentences, each adding distinct value (purpose, output, cost). Information is front-loaded and there is no redundancy or filler.

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?

The tool is simple, and the description adequately covers purpose, output, and cost. Given the lack of annotations and output schema, it could mention error cases or rate limits, but for a straightforward API call it is reasonably complete.

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 schema already provides descriptions for all three parameters (input, model, voice), so the description adds no additional parameter-specific context. The billing note is related to input length but does not enrich the understanding of any parameter beyond what the schema offers.

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's function as text-to-speech via ElevenLabs and its output (MP3 URL). This distinguishes it from sibling tools like generate_image, and the purpose is immediately 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 usage for text-to-speech needs and warns about per-character billing, but it does not explicitly state when to use this tool versus alternatives or mention any exclusions. This is implied rather than explicit.

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