start_playback

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

With no annotations provided, the description carries full burden for behavioral disclosure. While 'Start playing' implies a state-changing action, it doesn't describe what happens (does it start from beginning? current position?), whether it requires specific conditions (session loaded), or what the output contains. For a mutation tool with zero annotation coverage, this is inadequate.

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, efficient sentence that directly states the tool's function with zero wasted words. It's appropriately sized for a simple action tool and front-loads the essential information immediately.

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 this is a state-changing tool with no annotations but with an output schema (which presumably documents return values), the description is minimally complete. It states what the tool does but lacks important behavioral context about prerequisites, effects, and relationships to other tools. The existence of an output schema helps but doesn't fully compensate for the missing usage guidance.

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% (though trivial since there are no parameters). The description doesn't need to compensate for any parameter documentation gaps. A baseline of 4 is appropriate for a zero-parameter tool where the schema fully documents the empty parameter set.

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 ('Start playing') and the target resource ('the Ableton session'), providing a specific verb+resource combination. However, it doesn't distinguish this tool from its sibling 'stop_playback' or explain the relationship between starting and stopping playback, which prevents a perfect score.

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 doesn't mention prerequisites (like needing a session loaded), when not to use it (if already playing), or how it relates to sibling tools like 'stop_playback' or 'fire_clip'. This leaves the agent with insufficient context for optimal tool selection.

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