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

The annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds that 1 is the normal reference value, which is useful context, but it does not say whether the change persists, how it interacts with the currently active avatar (no avatar identifier parameter exists), or whether the setting can be reverted.

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 short sentences with the core action front-loaded and the scale reference appended. No filler, no redundancy, and nothing an agent must skim past.

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 two-parameter tool with no output schema, the description is close to sufficient: purpose, targets, and the normal value are all present. The remaining gap is the optional talk parameter and whether the setting applies to the current avatar implicitly, which is not stated anywhere in schema or annotations.

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. It does map the two properties to their meaning — idle animation and talking animation — and supplies the reference point '1 is normal', which clarifies the scale. However, it never explains that talk is optional or what value is used when it is omitted, nor that values act as a multiplier over the 0.1–4 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 states a specific verb and resource: 'Set the avatar's idle and talking animation speed.' An agent can immediately tell this is a speed-tuning tool, distinct from siblings like set_sensitivity or set_avatar. It stops just short of naming how it differs from those siblings, but the verb+resource pairing is unambiguous.

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?

There is no guidance on when to use this tool versus alternatives, no preconditions (e.g. whether an avatar must be loaded), and no mention of what happens if talk is omitted. Usage is only implied by the word 'Set'.

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