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

Annotations already establish the safe-read profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds genuinely useful behavior beyond that: recommended voices are ordered first, all voices cover all content languages, and the listing is free.

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 sentence with the primary purpose front-loaded and the secondary facts (ordering, language coverage, cost) trailing. No filler.

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 carries more burden, and it does specify that entries include voice_id plus ordering and language behavior. It does not describe pagination or the rest of a voice's returned fields, a minor gap for a two-parameter listing tool.

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 both limit and recommended_only are already documented; baseline 3 applies. The mention that 'recommended storytelling voices come first' loosely connects to recommended_only but adds no format or syntax beyond the schema.

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 (list) and resource (AI narrator voices) and explicitly ties the result to its consumers by naming voice_id as the input for create_short and generate_voiceover. This distinguishes it from sibling list tools like list_languages or list_caption_styles.

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?

The description makes the use case clear: it returns voice_ids consumed by create_short and generate_voiceover, so an agent knows when to call it. It stops short of stating when *not* to use it or naming an explicit alternative.

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