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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the readonly nature is covered. The description adds transparent context about what the tool returns access to: the user's private NiceVois-trained or uploaded RVC voices, and signals that calling it is a prerequisite before conversion. This is meaningful beyond the structured annotations.

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?

The description is two sentences with no filler. It front-loads the primary use case and immediately follows with an actionable constraint, making the tool's purpose and invocation behavior easy to absorb.

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?

Given zero parameters, an output schema, and read-only annotations, the description provides the necessary context for a simple list-and-select tool. It states when to invoke it, what it exposes, and a behavioral rule that prevents the agent from prompting for unnecessary input. No critical guidance is 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?

The tool has zero parameters, so there is little parameter-specific semantics to add. The description reinforces the zero-input expectation by instructing the agent not to ask for a model ID first, which compensates for any potential ambiguity about required inputs.

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?

Description names a specific verb (list/select) and resource (private RVC voice models), and clarifies the exact use case: choosing one of the user's private NiceVois-trained or uploaded RVC voices for conversion. This clearly distinguishes it from sibling tools like create_voice_conversion or list_training_jobs without needing to inspect schemas.

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?

Explicitly states the condition for use: 'when the user wants to convert audio and you need to select one of their private NiceVois-trained or uploaded RVC voices.' It also gives a concrete behavior rule: do not ask for a model ID before calling. It lacks explicit when-not-to-use or alternative tool routing, but the clear trigger instruction is strong.

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