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

Annotations already declare destructiveHint=false, idempotentHint=false and openWorldHint=true, and the description reinforces the non-idempotency with a concrete consequence ('a second call with the same name is refused'). It also adds a real constraint the annotations don't convey — the 2–30 second recording requirement — and an ethical precondition (owner consent). Not a full 5 because the duplicate-refusal mechanics are largely repeated from the schema.

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?

A single dense paragraph with the core purpose front-loaded, followed by inputs, return shape, the non-idempotency warning, and the consent caveat. Each sentence carries information; the parameter enumeration is slightly redundant against the 100%-covered schema but not wasteful.

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?

An output schema exists, so return values need not be described — yet the description still names the key returned fields (id, name, voice type, engine) and how to use the id. With annotations covering the safety profile and the schema covering every parameter, the remaining behavioral gaps (non-idempotency, consent, length constraint) are all addressed.

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 100%, so the schema already documents all five parameters in detail (formats, size limits, enum languages, transcript matching). The description restates the inputs at a high level — name, language, spoken text, and audio via base64 or URL — but adds no syntax or format meaning beyond what the schema provides, so the baseline of 3 applies.

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 ('Create a cloned voice ... from a recording') and enumerates the required inputs, so the agent knows exactly what the tool produces. It routes to list_voice_profiles and speak, but never distinguishes itself explicitly from the sibling ensure_voice_profile, which appears to be the idempotent variant — a one-line contrast would have earned a 5.

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 clear operational context: check list_voice_profiles first, pass the returned id to speak, and only clone with the owner's consent. It names a concrete prerequisite tool, though it stops short of stating when to prefer this over ensure_voice_profile.

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