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

Goes well past the annotations (readOnlyHint=false, destructiveHint=false, openWorldHint=true) by disclosing the unit cost of a voice slot, that 'a charge applies', that the clone is ready 'in seconds', and that the result is persisted in the voice list as a reusable voice_id. It also surfaces a consent/permission obligation and a public-figure clearance rule that no structured field carries.

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?

Front-loads purpose and sample quality, then cost and the quote workflow, which is the right order for an agent deciding whether to act. Minor waste: the 'asset id from the library or an https link' sentence and the quote_only pricing note largely restate the schema, and the PRICE block is set off in a slightly fragmentary register.

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?

There is no output schema, and the description compensates by naming the return ('Returns voice_id and name') and the side effect (a voice slot consumed, entry saved in the voice list). Cost, latency, consent, and the quote-first path are all covered, so nothing an agent needs before invoking is missing.

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 coverage is already 100%, so the baseline is 3, but the description adds value the schema lacks: what counts as an acceptable recording ('one person talking and nobody else, no music and no background noise... about a minute or more'), and that name plus recordings are the fields that actually trigger a run. tags and remove_background_noise are only covered by the schema, hence not a 5.

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: 'Make an instant voice clone of a real person from one or more clips already in your library', with the input source and output (voice_id) named. It implicitly separates itself from design_voice/voice by requiring real recordings rather than a text prompt, but never names a sibling, so an agent must infer that boundary.

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?

Gives a concrete operating sequence: 'Pass quote_only: true first to get the exact price' and 'To run it (not for a quote) send name, recordings', which is especially useful since the schema marks zero required parameters. It does not say when to prefer design_voice or an existing voice from list_voices instead, so the sibling decision is left implicit.

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