9router TTS

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

The annotations leave all hints false, so the description bears full responsibility for disclosing behavior. It only says 'Shape varies by host', which does not explain side effects, response formaat, failure modes, or what 'host' means in practical terms.

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 definition is extremely brief, but the sentence 'Shape varies by host' does not earn its place because it is undefined and ambiguous. There is no meaningful structure or front-loading beyond the tool title/name.

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 four parameters, host-dependent behavior, and a non-trivial sibling context, the description is near-empty. It does not explain how to invoke the tool correctly, what outputs to expect, or how the 'host' variation manifests, leaving the agent without critical context despite an output schema being present.

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% and the description adds nothing about the four parameters. An agent cannot infer what 'model', 'voice', or 'timeout_seconds' do beyond their names, and no format or constraints are given for 'text'.

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 identifies a specific function, text-to-speech, which is clearly distinct from siblings like nine_stt (s peech-to-text) and other nine_* tools. However, 'Shape varies by host' is vague and doesn't specify the exact operation such as 'generate an audio stream from provided text'.

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 guidance on when to use this tool versus alternatives such as nine_chat, nine_image, or nine_video. The only textual hint, 'Shape varies by host', is an opaqque caveat, not actionable usage guidance.

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