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

Annotations only state readOnlyHint=false and openWorldHint=true. The description adds valuable behavioral detail: it is a mutable operation (add), requires approved media host URLs, and specifies coordinate and frame conventions. It does not mention error handling or side effects, but it goes beyond the annotations meaningfully.

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 three sentences long, with the first sentence immediately stating the core action and target. The second and third sentences efficiently add essential constraints and encoding details. No words are wasted.

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?

This is a complex tool with 16 parameters, nested objects, and no output schema. The description provides a few high-level constraints but does not explain required fields, return values, failure modes, or the semantics of many parameters. It is insufficient for an agent to confidently invoke the tool without further information.

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 input schema has no descriptions for any of its 16 parameters (0% coverage). The description compensates partially by explaining that positions are center coordinates and timing/trim values are frame-based, which clarifies parameters like position, startFrame, and trimStartFrame. However, many parameters (e.g., volume, size, transform, name) are left unexplained, so it only partially bridges the gap.

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 verb and resource: 'Add a video or audio clip to a Picorn timeline.' It also highlights that positions are center coordinates and timing is frame-based. However, it does not explicitly distinguish itself from sibling tools like picorn_video_import_media, so it lacks full differentiation.

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 context by saying 'add... to a Picorn timeline,' and it provides a key constraint (source URLs must use an approved public media host). It does not explain when to prefer this tool over alternatives or when not to use it, especially given the sibling tool picorn_video_import_media.

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