mix_start_peak_watch

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

Annotations indicate readOnlyHint=false and openWorldHint=true, so the description correctly implies a state-changing operation. The description adds the concepts of 'process-persistent' and 'sampled', and notes it returns the first frame, which goes beyond annotations. However, it does not disclose side effects such as whether starting multiple watches replaces existing ones, resource consumption, or how to stop it. Since annotations cover the basic safety profile (non-destructive), the description adds some value but lacks depth on behavioral nuances.

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?

The description is a single, tightly worded sentence that front-loads the primary action ('Start') and immediately conveys the resource and expected return. Every word earns its place; there is no fluff or repetition. It is appropriately concise for a tool that relies on schema for parameter details.

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?

Given the tool starts a persistent process, the description is incomplete. It does not explain how to retrieve subsequent frames (presumably via mix_get_peak_watch) or that the watch must be explicitly stopped (mix_stop_peak_watch). It also omits any mention of the watch scope (e.g., which mixer tracks are covered) beyond what parameters imply. An agent unfamiliar with the workflow may not know the sequence of calls. The output schema exists but is not shown; the description still should provide lifecycle context.

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?

All four parameters are fully documented in the schema with descriptions and defaults, and schema description coverage is 100%. The description itself adds no parameter-specific information beyond what the schema provides, so it does not compensate for any gaps. Baseline of 3 is appropriate because the schema carries the semantic load.

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 clear action ('Start') and a specific resource ('process-persistent sampled peak watch') with an explicit outcome ('return its first frame'). It is distinguishable from siblings like mix_get_peak_watch (which presumably reads existing watches) and mix_stop_peak_watch, though it does not explicitly name them. The term 'mixer' is only in the title, not the description, but the tool name and title provide sufficient context. Slight gap: no explicit mention of what a 'peak watch' is for, but the action 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?

The description provides no guidance on when to use this tool versus alternatives. It does not mention that this should be called before mix_get_peak_watch, nor that mix_stop_peak_watch should be used to end the watch. There is no indication of prerequisites or typical workflow. An agent is left to infer usage from the tool name and siblings, which is insufficient.

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