stop_playback

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does not state that this is a read-only or mutating operation, though 'Stop' implies a mutation of playback state. It also lacks information about side effects, such as whether it resets the playback position or stops all clips. This is a simple tool, but the lack of any behavioral details beyond the single verb is a gap.

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, concise sentence that exactly states the tool's action. There is no wasted verbiage, and it is appropriately short for such a simple tool.

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 there is an output schema provided, so the return value is likely documented there. The description does not specify the effect on current playback (e.g., does it stop just the session or also stop all clips?), which could be important for an agent to know. However, for a stop action, the purpose is clear enough. The description is missing some context about side effects, but overall it is adequate for a zero-parameter tool.

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 tool has zero parameters, and schema description coverage is 100% (since there are no properties). The baseline for 0 params is often 4, but since there are no parameters to explain, the description doesn't need to add any parameter info. However, the description doesn't add any context about return values or arguments; it's minimal but sufficient. Given the simplicity, a score of 3 is reasonable, as there is nothing to add but also nothing missing.

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 the action clearly: 'Stop playing the Ableton session.' This is direct and specific about what the tool does. It does not explicitly distinguish from the sibling tool 'stop_clip', which likely stops a clip rather than the session, but the resource ('session') 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 gives no guidance on when to use this tool versus 'stop_clip' or 'start_playback'. While the purpose is clear, there is no mention of prerequisites, such as whether a session must be playing or if it can be called anytime. It also doesn't clarify the difference between stopping the session and stopping a clip, which could be confused.

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