Generate speech with word timing / captions

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

The description discloses that the API returns a zip containing audio, JSON timing, SRT, and VTT, and that the tool extracts and saves each file. This goes beyond the annotations (readOnlyHint=false, destructiveHint=false) by specifying the actual write behavior and output artifacts, providing useful context.

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 three sentences, front-loaded with the primary purpose. Each sentence adds value: purpose, extraction behavior, and compatibility note. There is no fluff or repetition of schema fields.

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 description covers the core behavior and artifact types but lacks information about return values (since there is no output schema) and relies on the sibling for parameter details. It does not mention what happens after saving (e.g., returns file paths or nothing), leaving a gap for a complex 11-parameter tool.

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 low (45%), so the description must compensate for undocumented parameters. However, it only references 'the same voice/model/prosody options as wellsaid_generate_speech' without explaining any specific parameters or their semantics. It does not add meaning beyond the schema for most of the 11 parameters.

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 renders text to speech and additionally provides word-level timing and caption files. It distinguishes itself from the sibling wellsaid_generate_speech by explicitly mentioning the timing/caption extraction and referencing the sibling for option compatibility.

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 this tool is the right choice when timing/captions are needed by saying 'and also get word-level timing and caption files.' It also references the sibling 'wellsaid_generate_speech' for option compatibility, but does not explicitly state when not to use it or contrast alternatives beyond that sibling.

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