change_video_speed

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

With no annotations provided, the description carries full behavioral burden. It states that audio is also affected and that a status message is returned, but it does not disclose potential side effects like re-encoding, pitch preservation, or handling of output file overwrites. This is adequate but not rich.

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 concise, well-structured with an Args section and Returns note, and front-loaded with the primary purpose. Every sentence contributes useful information without redundancy or 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?

For a relatively simple tool (3 scalar parameters, no enums or nested objects), the description covers the tool's effect, parameter meanings, and return value. The output is a simple status message, so no additional return details are necessary. The presence of an output schema (even if not shown) further reduces the need to explain return values.

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?

Even though the input schema has no descriptions (0% coverage), the tool description itself includes detailed parameter explanations with examples and constraints (e.g., speed_factor must be positive, example values 2.0/0.5). This fully compensates for the schema's lack of semantic detail.

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 uses a specific verb ('Changes') and resource ('playback speed of a video'), clearly indicating the tool's function. It distinguishes itself from siblings like 'set_video_frame_rate' or 'trim_video' by focusing on playback speed and explicitly including audio.

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 clear context for what the tool does but does not explicitly state when to use it over alternatives or when not to use it. There are no exclusions or references to sibling tools. Usage is implied by the purpose, but no explicit guidance is given.

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