ACTION_VOLUME

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

With no annotations supplied, the description carries the full burden and does meaningful work: it names the return fields (volume_success/volume_current/volume_max), warns that value is a percentage while volume_current/volume_max are system steps (e.g. 0-15) and thus not directly comparable, and explains that string arguments support ${var} interpolation with results returned as a variable-snapshot JSON. It omits any mention of permissions, whether mute is per-stream, or failure modes, which keeps it short of a 5.

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 compact and front-loads the operations before the output contract and the percentage caveat, so the most important information comes first. Minor noise: a doubled punctuation mark and a slightly clipped telegraphic style, but no sentence is wasted.

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 tool with no output schema and no annotations, the description supplies the output field names, the key unit-mismatch warning, and the interpolation convention. Gaps remain around per-stream mute behavior, error handling for the require/on_error parameters, and the default time out, but nothing essential to a correct first call is missing.

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, but the description adds real meaning beyond the schema by explaining the percentage-vs-system-step distinction that the schema only hints at, and by framing string parameters as ${var}-interpolatable. The stream and on_error semantics are left entirely to the schema.

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 opens with a clear verb set and resource: "音量：设置、读取、增厉、输出" (read, set, increment/decrement, mute), which maps directly onto what the tool does. It does not, however, differentiate itself from sibling audio tools like get_audio_info or ACTION_GET_AUDIO_STATE, so an agent must infer the boundary itself.

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?

Usage is only implicit: the enumeration of operations implies when each mode applies, but there is no explicit statement of when to choose this tool over ACTION_GET_AUDIO_STATE or ACTION_MEDIA_CONTROL, and no exclusions are given.

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