change_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, but it only states that playback speed changes. It does not mention side effects such as whether audio pitch is preserved, whether a new file is created, or whether an empty output_path means in-place modification. For a mutation operation, this is a significant transparency gap.

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 front-loaded with the primary action in the first sentence, followed by a compact and well-formatted legend for the speed parameter. Every line serves a purpose, with no filler or redundant content.

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?

An output schema is present, so return values need not be explained in the description. However, the tool lacks critical context around file handling—specifically, what an empty `output_path` means and whether the input file is overwritten. This makes the description minimally viable but not fully complete for safe invocation.

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 meaningful semantics to the `speed` parameter by defining 0.5 = slow motion, 1.0 = normal, and 2.0 = 2x faster, which the schema does not provide. Although `input_path` and `output_path` are left unexplained, their purpose is conventional; the speed legend is a strong compensation given the 0% schema description coverage.

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: changing video playback speed, with concrete speed values (0.5, 1.0, 2.0) that reinforce the meaning. It is a specific verb+resource statement, and although it doesn't explicitly distinguish from siblings, no other listed tool handles playback speed, so it is unambiguous.

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, no exclusions, and no context about related operations like reversing or freezing video. Usage is only implied by the tool's name and purpose, which is insufficient for routing an agent when a large set of sibling tools exists.

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