list_local_cameras

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety and scope are covered. The description adds enumeration domain (DirectShow/Windows) and the output-name convention, but says nothing about failure/empty-list behavior or what happens when no devices are found.

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 with the core action front-loaded; the second sentence packs the device-name convention without preamble. No filler or restated title text.

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?

For a zero-parameter, read-only list tool with no output schema, the description covers what is enumerated, the platform, and how to use the result — enough to call it correctly. It stops short of 5 only because nothing is said about the shape of the response (ordering, empty results).

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 takes zero parameters, so the baseline for this dimension is 4. The description correctly adds no parameter detail because none exists, and instead documents the returned device-name format, which is the only input-like value an agent needs.

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?

Clear specific verb and resource: 'List video devices on the PC running this server', with platform scope (DirectShow, Windows) that pins down exactly what is enumerated. It does not explicitly contrast itself with the closest sibling, get_camera_snapshot, so it stops short of the top band.

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?

Gives real usage context: a phone-as-webcam appears in this list, and the returned name is consumed as DUET_CAMERAS="name=dshow:<device name>". It lacks explicit when-not guidance or a named alternative (e.g. 'use get_camera_snapshot to capture an image'), which keeps it out of the 5 band.

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