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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds real value by disclosing what the result set contains (favourites, recent voices, clones) and that it is account-scoped. It says nothing about ordering, pagination, or whether voices include metadata needed for generate_voice.

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?

One short sentence, front-loaded with the key scoping fact (the account's own voices) and followed by the enumeration of categories. No wasted words. The sentence fragment style omits an explicit verb but costs nothing in comprehension.

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?

For a simple, annotation-covered, zero-required-param read tool with no output schema, the description does enough: it fixes scope and points at the consumer tool. The main residual gap is whether returned entries include voice IDs usable directly in generate_voice, which the agent must assume.

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 parameter ownedOnly is documented in the schema as "Only the account's clones", so the schema carries the burden. The description's mention of "its clones" loosely aligns with that flag but adds no syntax or default behavior. Baseline 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 resource scope: the account's own voices (favourites, recent, clones) intended for generate_voice. An agent immediately knows this is a personal voice listing, not a catalog search. It stops short of naming the closest sibling, search_voices, so the boundary is implicit rather than explicit.

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 phrase "for generate_voice" implies the downstream purpose (pick a voice ID to synthesize), which is useful usage context. However, there is no explicit when-to-use vs. when-not, and with search_voices in the sibling set the agent must infer that this one is personal-only and that one is broader. Implied usage only.

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