speak_text

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

No annotations are provided, so the description carries the full burden. It states that the tool synthesizes and plays audio, but does not disclose whether it blocks, its synchronicity, network requirements, resource usage, or error behavior. The returns section is vague.

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 well-structured with a brief intro followed by a clear Args list. It front-loads the action and minimizes fluff. The Returns section is minimal but acceptable given output schema exists. Could be slightly more concise but overall effective.

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 6 parameters, no annotations, and an output schema (implied), the description covers parameters well but lacks context on dependencies (e.g., VOICEVOX service), potential errors, or audio device requirements. It is adequate but not fully 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?

Schema description coverage is 0%, so the description must compensate. It fully explains each parameter (text, speaker, speed, pitch, intonation, volume) with ranges, defaults, and the speaker fallback to environment variable. This adds substantial meaning beyond the bare schema.

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 performs text-to-speech synthesis with VOICEVOX and plays from speakers. It distinguishes from sibling 'list_speakers' by referencing it for speaker IDs, and from 'save_audio' by implying real-time playback.

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 mentions the default speaker from environment variable and references list_speakers for speaker IDs, but does not provide explicit when-to-use or when-not-to-use guidance compared to save_audio. Usage context is implied but not formally defined.

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