set_crossfade_assign

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

The annotations already provide idempotentHint=true and destructiveHint=false. The description adds critical behavioral context: that the tool does not move the crossfader or change track volume immediately, and that repeating the same assignment has no additional effect. This clarifies the exact scope of the tool's action, which is beyond what annotations alone convey.

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 extremely concise: four sentences covering purpose, behavior, recommended next step, and idempotency. Every sentence adds value and no word is wasted. It is front-loaded with the core action, making it easy for an agent to quickly understand the tool's primary function.

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 that the tool is simple (2 parameters, no enums, no nested objects), the description, annotations, and schema together provide a complete picture. The description explains what the tool does, what it does not do, the correct usage pattern, and idempotency. The presence of an output schema (though not detailed) and clear annotations further ensure the agent has all necessary 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?

The input schema covers 100% of the parameters with clear descriptions (e.g., assign: '0 is A, 1 is none, 2 is B'; track_index: 'zero-based index of a regular track'). The description does not add new parameter details beyond stating the track is regular and the assignment options are A/none/B. Since schema coverage is high, the description's marginal addition is minimal, resulting in a baseline score of 3.

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 clearly states the action ('Assign one regular track to crossfader side A, neither side, or side B') using a specific verb and resource. It distinguishes from the sibling tool 'set_crossfader' by noting that this does not move the crossfader, and explicitly mentions that repeating the same assignment has no effect, which differentiates it from other track operations.

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 explicit usage guidance: it says this tool does not move the crossfader or change volume, and directs the agent to 'use set_crossfader afterward to blend the A/B groups.' It also implies when not to use (if immediate volume change is needed) and hints at idempotency by stating repeating has no effect. This completely addresses when and how to use the tool alongside alternatives.

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