start_playback

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

With no annotations, the description carries the transparency burden, but it only says playback starts. It does not disclose side effects such as whether playback begins from the current playhead, whether it can interrupt existing playback, or any state assumptions.

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 minimal and front-loaded, with a clear one-line action and a brief parameter explanation. No filler or redundant content is present.

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?

The tool is simple and an output schema exists, so return-value documentation is not needed. However, the description lacks preconditions, behavior on repeated invocation, or relationships to other transport controls, so it is only partially complete.

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 description adds meaningful context to the user_prompt parameter by labeling it as the 'original user prompt' used for telemetry, which is not evident from the raw schema. It does not fully specify optionality or format, but this is the only parameter and its purpose is clear.

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 a concrete action and resource: 'Start playing the Ableton session.' It is distinguishable from sibling tools like stop_playback, though it doesn't explicitly contrast itself with alternatives.

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?

No guidance is given on when to use this tool versus similar transport or session controls. The agent is left to infer applicability from the name alone.

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