Reframe video

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

Annotations already indicate readOnlyHint=false, so the agent knows it's a mutating operation. The description adds valuable behavioral details: it is a 'Paid render' and 'returns the served URL of the reframed video', which explains cost and output. This goes beyond the annotations and does not contradict them.

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 concise sentences with zero waste. The first sentence states the core purpose and includes an example, the second adds cost and return information. Information is front-loaded efficiently.

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?

With only two parameters and no output schema, the description explains the return value (served URL) and cost (paid render). It does not mention potential limitations like supported formats or file size, but for a tool of this simplicity, the essentials are covered.

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 100% — both 'video' and 'aspectRatio' have descriptions. The tool description adds an example of aspect ratio conversion but no new parameter semantics beyond the schema. Per baseline, a score of 3 is appropriate when the schema already does the heavy lifting.

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 states a specific verb ('reframe'), a resource ('video'), and the exact purpose ('to a different aspect ratio') with a concrete example (16:9 → 9:16). This clearly distinguishes it from sibling tools like edit_video or clip_video, which focus on other video transformations.

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 usage for aspect ratio conversion and mentions 'smart subject tracking' and 'Paid render', but does not explicitly compare with alternatives or state when not to use. Since no sibling tool handles aspect ratio specifically, the intended use is clear, yet the lack of explicit exclusions prevents a perfect score.

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