design_voice

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

Annotations already declare it is a non-read-only, open-world, non-destructive operation. The description adds real behavioral detail beyond that: it writes three mp3 files to specific paths (generated/voice-<name>-1..3.mp3 when session-scoped, otherwise _library/voices/) and surfaces them on the Assets tab. It stops short of saying whether re-running or saving overwrites anything.

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?

It is front-loaded with the purpose and stays within a few sentences, with every clause carrying information. The parenthetical file-path detail makes the middle slightly dense, but nothing is redundant.

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 6-parameter, no-required-params tool with no output schema, the description covers the design/save lifecycle and where samples land. It does not clarify the default behavior when session is omitted beyond the library-path hint, a minor gap.

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 coverage is 100%, so the baseline is 3. The description adds value by explaining how save and name interact — save carries a sample's save id and name labels the kept voice — which is the trickiest part of the two-call flow, pushing it slightly above baseline.

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?

It states a specific verb and resource ('Design a new ElevenLabs voice') and gives a concrete example query ('warm German woman, 40s, calm, slow'). The word 'new' distinguishes it from sibling voice tools like change_voice, clean_voice, and voices, which act on existing 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?

The description lays out the two-phase workflow explicitly: call once to write three samples, then call again with save=<sample save id> plus name to keep one. That is clear context for correct invocation, though it states no when-not-to-use conditions and never names an alternative sibling.

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