Change playback speed

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

With no annotations, the description carries the full burden of behavioral disclosure. It adds the useful detail that audio pitch is preserved and explains factor semantics, but it does not disclose what happens when output_path is omitted (e.g., whether it overwrites the source or writes to a default location), nor does it describe return behavior. This is a notable gap for a write operation.

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 exceptionally concise: two sentences, clear verb-first structure, and every word earns its place. The examples are embedded efficiently without any fluff.

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 absence of annotations and an output schema, the description adequately covers the core functionality and parameter semantics, but it leaves a significant gap: the behavior when output_path is not provided. It also does not mention any side effects or processing limitations. This makes it a minimum-viable description, not fully complete.

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 all three parameters with 100% coverage, giving a baseline of 3. The description goes beyond the schema by providing concrete examples for 'factor' (2 = twice as fast, 0.5 = half speed) and adding the audio-pitch-preservation context, which enhances parameter understanding.

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 up or slow down a video' identifies a specific verb and resource, and the examples (factor 2, 0.5) clarify exactly what it does. This distinguishes it from siblings like resize_video or adjust_volume.

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 clearly implies when to use the tool: whenever a video's playback speed needs changing. It provides concrete factor examples, giving clear context. However, it does not explicitly mention alternatives or exclusions, so it stops short of a perfect score.

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