Change playback speed

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

The description discloses rich behavioral details beyond annotations: default time-stretching with chained atempo stages, keep_pitch behavior for tape speed-up, drop_audio option, and independent audio_speed. Annotations are minimal (readOnlyHint: false, destructiveHint: false), so the description carries the burden and does so thoroughly, explaining how audio is processed and how options affect output.

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?

Two sentences total: the first states the core purpose, the second elaborates on key behavioral details. Every phrase earns its place, with no filler. The structure is front-loaded and efficient.

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 the tool (7 parameters, shared encode options, output schema), the description captures the essential behavior: speed adjustment, independent audio control, pitch handling, and audio discard. The output path behavior is covered in the schema. No critical behavioral context is missing.

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 schema already describes most parameters with 86% coverage, but the description adds interaction semantics: it explains that audio is time-stretched by default, what keep_pitch false does, and how audio_speed relates to speed. This adds contextual meaning beyond individual parameter descriptions, enhancing understanding of how they work together.

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's function: 'Speed a clip up or slow it down, video and audio independently.' It identifies the specific resource (a clip) and distinguishes it from sibling tools like trim or transform by emphasizing independent video/audio speed control. This is a specific verb+resource description with clear scope.

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 implies when to use the tool (speeding/slowing clips) and explains key behavior, but it does not explicitly mention when not to use it or compare to alternatives. There is no explicit 'instead of X' guidance, but the context of audio pitch handling gives some situational awareness. This is adequate but lacks direct exclusions.

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