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

Annotations already flag destructive=true, idempotent=false, readOnly=false; the description adds real behavior beyond that: validation of every resulting stack and existing credential binding before a frozen publication, the constraint that the environment is never caller/STT input, and a concrete 400 refusal path for has_language_axis:false engines that names the offending field. This is meaningful error and side-effect disclosure.

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?

Three dense sentences with no filler, front-loading the publish action before the validation and engine-refusal details. The jargon is heavy but each sentence carries distinct information.

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 16-parameter destructive mutation with no output schema, the description covers validation, freezing, ambient-pin constraints, and a specific 400 failure mode. Missing pieces are replacement semantics for omitted fields and permission requirements, but the core behavioral surface is covered.

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 only 50% across 16 parameters, so the description is expected to compensate. It clarifies two areas well — locale overrides may set only exact voice/transcriber/greeting, and audio_environment is pinned and non-input — but leaves model, voice, language, transcriber, first_message, system_prompt and others without added semantics.

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?

States a specific verb (publish) and resource (an agent's shared voice stack), plus the secondary payloads it carries (version-pinned audio environment, language profiles). The 'publish/frozen' framing clearly distinguishes it from the read sibling get_agent_voice_stack, though it never names alternatives explicitly and the verb differs from the tool name 'set'.

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 word 'explicitly' and 'publication is created' imply this is the deliberate write counterpart to the get tool, but the description never states when to use this versus update_agent or PATCH-style updates. Usage is inferable rather than spelled out.

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