tts

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 does disclose one real behavioral trait — outputs are cached WAVs — and sketches the return shape, which is useful. However, it says nothing about permissions, whether files are written to disk, latency, or how the cache is invalidated.

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?

It is a single short line with no wasted words and the core action is front-loaded. However, the telegraphic arrow-and-brace notation is cryptic and forces the agent to decode rather than read, trading brevity for clarity.

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?

With no output schema, the description usefully encodes the return shape ({durations, cached}), which offsets some of the burden. But for a four-parameter tool with half its parameters undocumented, the definition leaves too much unspecified to be considered 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?

With only 50% schema coverage, the description should compensate for undocumented parameters, but it mentions none of the four (lines, speed, voice, lexicon). The trailing object notation describes the response, not the inputs, so it adds zero meaning beyond the schema fields.

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?

States a specific verb and resource ('Synthesise narration') and notes the artifact produced (cached WAVs), so an agent can tell this is a text-to-speech tool. It does not differentiate from siblings, though the sibling list (probe, ocr_region, chart_extract, etc.) makes it reasonably distinct by domain.

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?

There is no when-to-use guidance, no mention of prerequisites, and no alternatives named. The parenthetical '(cached WAVs)' hints that returns may be reused from cache but gives no condition under which that matters.

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