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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world. The description adds cost/statefulness context beyond that: no voice is created, no speech is generated, no credits are spent, which reassures the agent this is a free, side-effect-free read. It does not describe the private sample link's access semantics or failure modes.

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?

Three short sentences, front-loaded with the core action and backed by the constraints. The middle sentence about the voice already being selected is slightly incidental but still informative; nothing is wasted.

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-value detail is unnecessary. For a single-parameter, read-only tool the description covers purpose, preconditions, and cost profile adequately; only sibling differentiation and id-handling remain thin.

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% and the single artistId parameter is fully documented in the schema as 'the existing cast artist'. The description adds no extra meaning about the identifier (e.g. how to obtain it or what happens with an unknown id), so the schema carries the load.

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: reading the artist's saved speaking voice plus its revision, with the optional sample link noted. It is clearly distinguishable from the write-oriented siblings (voice_choose, voice_record, voice_status), though it does not explicitly distinguish itself from studio_artist_voices_list or studio_artist_voice_status, where overlap in meaning is possible.

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 context for when the tool applies: a recorded voice is already selected for the artist's Film dialogue, implying preconditions are met. It does not name an alternative sibling or state exclusions, so it stops short of a full when/when-not routing statement.

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