AbletonMCP

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 states the action ('stop playing') but doesn't mention side effects (e.g., does it mute the clip, remove it, or just pause it?), permissions required, or error conditions. This leaves significant gaps for an agent to understand the tool's behavior.

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, clear sentence with zero waste. It's front-loaded and efficiently conveys the core action without unnecessary details, making it easy for an agent to parse quickly.

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 complexity of a tool that modifies clip state (implied by 'stop'), no annotations, no output schema, and low parameter coverage, the description is inadequate. It doesn't address what happens after stopping, potential errors, or how to verify success, leaving the agent with incomplete context for reliable use.

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 no information about the parameters beyond what the schema provides (two required integers: track_index and clip_index). Since schema description coverage is 0%, the baseline is low, but the description doesn't compensate by explaining what these indices mean or how to determine them, resulting in a minimal viable score.

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 'Stop playing a clip' clearly states the verb ('stop') and resource ('clip'), making the purpose immediately understandable. However, it doesn't differentiate from sibling tools like 'stop_playback_tool' or 'fire_clip_tool', which might have related functionality, so it doesn't reach the highest 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?

No guidance is provided on when to use this tool versus alternatives. For example, it doesn't clarify if this is for stopping a specific clip versus general playback (as in 'stop_playback_tool'), or if there are prerequisites like the clip needing to be currently playing. The description lacks context for decision-making.

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