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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered; the description restates that and adds the useful 'no generation or credits' cost context. It says nothing about pagination behavior (limit/offset exist) or result ordering, so the added behavioral value beyond annotations is modest.

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, zero filler, and the core capability is front-loaded before the handoff instruction. Every sentence earns its place.

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 paginated list tool with no output schema and six parameters, the description never addresses pagination, defaults, or the filters an agent would likely want. The handoff and cost notes are valuable, but key operational details are 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 description coverage is only 33% (search and language only), so the description must compensate, but it explains none of limit, offset, gender, or the source enum values. 'Library or this workspace's voices' loosely gestures at source and 'languages' at the language filter, but four of six parameters remain undocumented in both places.

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 ('Lists ... voices') and delimits scope to 'eligible library or this workspace's voices', while naming the returned fields (provider voice_id, languages, previews). That is enough to separate it from all siblings, including composer_voice_line which it explicitly hands off to.

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 an unambiguous workflow: 'Select a voice with the user; pass its voice_id to composer_voice_line, never a record UUID.' It names the downstream tool plus the exact value to supply and one explicit pitfall (don't pass a record UUID). Little is left to inference.

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