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

Beyond the annotations, the description discloses important behavior: tasks are billable, backend validation is authoritative, rejected or unconfirmed submissions must not be auto-resubmitted, and returned identifiers must be preserved for later workflow steps. It also clarifies that omitting technical identifiers applies only to user-facing replies and not to tool results. This adds meaningful operational context without contradicting the 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 a long block of generic creation-tool boilerplate that repeats policy-level instructions likely shared across many siblings. It buries the few design_voice-specific details inside verbose guidance and is not front-loaded around what the tool actually does or when to use it.

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 the complex nested schema, rich annotations, and an output schema, the description covers operational mechanics reasonably well: defaults lookup, schema lookup, file bindings, session/version handling, and identifier preservation. What it does not provide is domain context for voice design itself, such as what inputs produce which kind of voice output or why an agent would choose this tool over clone_voice or generate_speech.

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 parameter definitions already carry much of the load. The description still adds useful cross-parameter meaning: model can be omitted to use the default, explicit model selects a public task model, session_title starts a new topic, session_id continues one, and session_id plus base_run_id versions an existing run. It also warns that flat model parameters and legacy reference_images/reference_audio are not accepted, which is not obvious from the schema alone.

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 says it creates one independent billable Studio task, which is a concrete operation, but it never states that this tool designs a voice or what kind of voice-design task it performs. It also does not distinguish design_voice from siblings like clone_voice or generate_speech, leaving the agent to infer the actual purpose from the name alone.

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 gives procedural guidance for model defaults, schema lookup, session_title vs. session_id, and base_run_id versioning. However, it never says when to use design_voice instead of another sibling creation tool, so tool selection remains implicit rather than explicitly guided.

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