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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is established. The description adds useful behavioral context by noting 'the chosen voice carries across parts when you continue my story,' which hints at persistent selection state beyond a simple read-only list. This goes beyond what the annotations alone provide.

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 three short sentences with no filler. It front-loads the core purpose, then provides the Audio Lab catalog relationship and the persistence behavior, all of which are relevant and likely to help an agent select and invoke the tool correctly.

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 zero-parameter, read-only listing tool with an output schema, the description is complete. It names the resource, distinguishes the catalog context, and explains a relevant behavioral nuance. There are no missing details that would prevent correct invocation.

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 input schema has no parameters, so the baseline is 4. The description adds meaning by indicating the returned voices include accent and locale details, and the output schema is present to cover return structure. There is no parameter documentation burden to satisfy.

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?

The description states a specific verb and resource: 'List Story narration voices with accent and locale.' It is clear that this tool lists voices for Story narration, which distinguishes it from sibling tools like list_talking_short_actors and list_storyboard_themes. However, it does not explicitly differentiate itself from list_audio_lab_voices beyond saying 'Same catalog as Audio Lab,' which leaves some ambiguity about when one is preferred over the other.

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 implies that this tool is for Story narration voice listings and notes the relationship to Audio Lab, but it does not explicitly state when to use this tool instead of list_audio_lab_voices or other voice-related tools. There is enough context for basic selection but no explicit exclusions or alternative routing.

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