Text To Speech

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

No annotations are provided, so the description is the sole source of behavioral information. It discloses that the tool returns a saved audio file path and names the backend (kokoro), but does not elaborate on file lifecycle, synchronous/asynchronous behavior, or failure modes.

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?

Two sentences, immediately front-loaded with the action and output format. Every phrase adds value; the only mildly cryptic element is 'NaN API TTS' but it does not waste space.

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 five parameters and no output schema, the description provides a clear return value (file path) and points to a companion tool for voice selection. It does not explain output file management or error behavior, but the schema covers input formats, making it 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?

Input schema covers 100% of parameters with descriptions and examples, so the baseline of 3 applies. The description's mention of list_voices for the full catalog adds a complementary hint but does not exceed schema detail.

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?

Clearly states 'Synthesize audio from text' with a specific verb and resource. Distinguishes itself from siblings like list_voices and speech_to_text by focusing on synthesis and saving an audio file.

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?

Explicitly recommends using list_voices to discover voices, which gives context for voice selection. It does not explicitly contrast with speech_to_text, but the tool name and description make the use case obvious.

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