preview_voice

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

With no annotations, the description carries the full burden and discloses key behaviors: writes to <output_dir>/previews, auto-opens with the default player on Windows, playback is best-effort, and audio_path is still returned on failure. This is rich behavioral disclosure covering side effects, platform dependence, and error handling.

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 tightly written sentences with no filler. The primary purpose is front-loaded in the first sentence, and the second sentence packs essential behavioral details efficiently.

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 covers the core purpose, side effects, and failure behavior. The output schema exists, so return values are documented elsewhere. However, the lack of explicit parameter explanations is a gap that prevents this from being a fully self-contained description.

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 has zero parameter descriptions, so the description must compensate. It only loosely implies that 'text' is the content to render and 'voice' refers to a voice, but it never explicitly explains these or the 'play' parameter. This is a significant gap since an agent cannot reliably infer parameter meanings from the description alone.

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 states a specific action ('Render a short sample') and a clear purpose ('so you can hear a voice before a full render'), which distinguishes it from the full rendering sibling tools. The resource and scope are explicit.

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?

It clearly indicates the tool is meant for pre-render previews via 'before a full render', giving context on when to use it. However, it does not explicitly mention alternative tools like render_voiceover or render_long_voiceover, so it misses a direct comparison that would strengthen the guidance.

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