Set the playback rate of an audio item to alter its speed, with 1.0 for normal and lower values for slower playback, enabling time-stretching effects.
Adjust playback rate of an audio item. 1.0 = normal speed, 0.5 = half speed.
| Name | Required | Description | Default |
|---|---|---|---|
| rate | Yes | ||
| item_index | Yes | ||
| track_index | Yes |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, and the description gives minimal behavioral disclosure. It explains rate unit but doesn't mention range limits, whether pitch is preserved, or any side effects. The agent is left to infer behavior from the input schema.
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 short and front-loaded with the action. Every sentence is relevant, though more details could be added without becoming verbose. It is efficiently stated.
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 tool has 3 required parameters and no output schema, the description is too minimal. It lacks instructions on how to select the correct track and item, and what the effect entails (e.g., real-time, destructive). The agent may struggle to invoke it correctly without external knowledge.
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?
Schema coverage is 0% with no descriptions on parameters. The description adds meaning only for the 'rate' parameter by giving examples. The 'track_index' and 'item_index' are left unexplained, forcing the agent to rely on naming conventions alone.
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 tool adjusts playback rate of an audio item and provides common values (1.0 normal, 0.5 half). However, 'audio item' is somewhat vague and could be more specific, but the purpose is well understood.
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 on when to use this tool versus alternatives like adjust_pitch or other manipulation tools. There is no when-not-to-use or context for choosing this over siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.