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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: it returns a URL to generated audio, text defaults to a standard demo line, and passing the user's actual message previews exactly what they will hear.

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 prose is tight and front-loaded, with the return artifact stated in the first line. The Args block is well-organized but slightly verbose in places (e.g., repeating that text can be the user's reminder message).

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?

An output schema exists, so return-value detail is not required, yet the description still notes the URL. All five parameters are documented despite 0% schema coverage, leaving little an agent needs that 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?

Schema description coverage is 0%, so the description carries the full burden and does so thoroughly: voice_id's source (list_voices), text's default and intended use, the four allowed personality values (enums not present in the schema), language as a BCP-47 tag with example, and the 0.8–1.2 speaking_rate range.

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 opens with a specific verb and resource ('Generate a short audio sample of a voice') and states the intent ('so the user can hear it before choosing'). It is clearly distinguishable from siblings like list_voices, set_reminder_voice, and test_call, which do different things with voices.

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?

It gives concrete usage contexts: deciding between voices, or checking how the user's own reminder wording will sound. It does not name an alternative tool or state when not to use this one, so it falls short of explicit routing guidance.

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