cw_apply_mix

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

No annotations are provided, so the description carries the full burden for a mutation tool. It does disclose one useful trait — multiple channels are applied in a single round trip — but says nothing about atomicity (does a bad channel abort the whole batch?), permission/support requirements, or what is returned. The omission of panCC/volumeCC from the narrative also hides part of the mutation surface.

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 action and the batch benefit front-loaded, then the payload shape. Dense and essentially waste-free, though the second sentence's shorthand notation is terse enough to require a careful read.

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?

This is a mutation tool with a nested array parameter, no annotations, no output schema, and 0% schema description coverage — the heaviest possible burden on the description. It leaves out the CC variants, error/partial-application behavior, and any return semantics, which is not sufficient for a batch write operation.

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 must compensate, and it does partially: it gives the array shape, the required channel key, and the pan (-1..1) and volume (0..1) ranges. However, two of the five item properties (panCC and volumeCC) are never mentioned, so the semantics of the raw MIDI CC alternative path is left entirely to the schema's type constraints.

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 pairs a specific verb (set) with specific resources (pan and volume) and adds scope: several channels in one round trip. That scope implicitly separates it from the single-target siblings cw_set_pan and cw_set_volume, but the description never names those siblings or states the distinction explicitly.

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 'several channels in one round trip' phrasing implies batch usage versus the single-channel setters, but there is no explicit when-to-use/when-not guidance and no mention of cw_set_pan, cw_set_volume, or cw_mixer_targets as alternatives. An agent has to infer the routing decision.

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