vmix_scene_template

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

The annotation already flags destructiveHint, and the description adds the useful constraints that sources must pre-exist and that output resolution is unchanged. It does not disclose post-conditions, such as whether existing scenes are overwritten or what error behavior looks like, but the annotations keep the baseline low enough that this is acceptable.

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 tight sentences that front-load the action and then state prerequisites and constraints. No filler words; every clause adds information.

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?

The core behavior (building scene layouts) and prerequisites are covered, and there's no output schema to explain. However, the dry_run parameter and the exact difference from vmix_scene_create are not addressed, leaving an otherwise decent description slightly incomplete for a 7-parameter tool.

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?

With 0% schema description coverage, the description must compensate. It does add meaning for layout (lists the valid values), sources ('must already exist'), and width/height ('must match preset'), but it leaves name, request_id, and dry_run semantically unexplained. It partially compensates but does not cover all parameters.

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 verb 'Build' and the resource 'scene', with layout variants enumerated. It does not explicitly differentiate from sibling vmix_scene_create, but the layout list makes the tool's scope reasonably distinct.

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 two useful conditions — 'Sources must already exist' and 'Canvas dimensions must match your vMix preset' — which give the agent a sense of when it is appropriate. However, it does not compare against alternatives such as vmix_scene_create, nor does it state when not to use this tool.

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