start_virtual_cam

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

With no annotations available, the description must disclose behavioral traits itself, but it only states the action without mentioning side effects, prerequisites, or error conditions (e.g., whether starting an already-running virtual camera fails). This leaves the agent without essential behavioral context.

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 a single, concise sentence that front-loads the core action with no filler words. It is appropriately sized for the tool's simplicity.

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?

Despite no parameters, the description does not clarify what happens after starting the virtual camera, such as how success is communicated or whether it is safe to start when already active. Given the absence of annotations and output schema, this is under-specified for complete context.

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 tool has zero parameters, and the input schema already reflects this with an empty properties object. Per the rubric, a description for a tool with 0 params receives a baseline of 4, and there is no parameter information to add.

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 specifies the action ('Start') and the resource ('the virtual camera'), making it unambiguous. It distinguishes from sibling tools like stop_virtual_cam and toggle_virtual_cam by explicitly naming the start operation.

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 no guidance on when to use this tool versus alternatives such as toggle_virtual_cam or stop_virtual_cam. There are no preconditions, use cases, or contextual hints to help an agent select it appropriately.

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