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

Annotations already declare this is a non-read-only, non-destructive, closed-world write, so the safety profile is covered. The description adds real behavioral context by explaining what the setting actually controls (when the mouth starts moving in response to audio level). It stops short of saying whether the value persists across sessions or what the default is.

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?

Two tight sentences: what the value means, then what to do with it. Front-loaded with the core semantics and no filler.

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 single-parameter, non-destructive configuration tool with no output schema, this covers the essentials: what is being tuned, the value range, and one tuning direction. Only minor gaps remain (default value, effect of lowering, persistence).

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 0%, so the description must carry the parameter burden. It does explain that 'value' is a normalized audio-loudness threshold and that higher values require louder audio, which is genuinely useful beyond the bare number type and 0-1 bounds. However, it does not state a default, unit rationale, or how the effect scales between 0 and 1.

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 ('Set') and a precise resource concept: the audio loudness threshold that gates the avatar's mouth movement. This is unambiguous and clearly distinct from siblings like set_speed or adjust_image, though it does not explicitly name any sibling for differentiation.

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?

Provides one concrete invocation cue, 'Raise it when the mouth never stops', which tells the agent when to use it in one direction. It does not cover the opposite case (lowering when the mouth barely moves), does not mention persistence or prerequisites, and does not point to troubleshoot_audio as an alternative when the problem is not sensitivity-related.

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