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

Annotations already declare idempotent=true, destructive=false, and readOnly=false. The description adds useful behavior beyond those annotations: the clip is empty, its effects reach every track below it while it runs, and the call returns the edit result.

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?

A single compact sentence conveys what the clip is, how its effects work, an example use, and the return behavior. There is no redundant restatement, and the core definition is front-loaded.

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 annotations covering safety and idempotency and an output schema covering the return, the description supplies the missing conceptual model: empty clip, effect scope, and the filter.add relationship. Nothing critical for correct invocation is missing, and return details are appropriately delegated.

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 description coverage is 80%, so most parameter meaning is already provided structurally. The description reinforces that track_id is a video track whose effects reach lower tracks and links the returned clip_id to filter.add, but it does not elaborate on duration_frames or at_frame beyond the schema, fitting the baseline for high 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 defines an adjustment clip as an empty video-track clip whose effects change everything below it while it runs, with colour grade/blur as examples. It clearly identifies the resource and effect mechanism, though it does not open with an explicit action verb, so the title carries part of the action.

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?

It gives a clear use case: a colour grade or blur over a stretch of the edit, and explains that effects are added via filter.add using the returned clip_id. It does not explicitly state when not to use it or compare it with alternatives, so it provides clear context without exclusions.

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