watchface_set_brightness

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

With no annotations, the description must disclose behavioral traits. It does not mention that this is a write operation, possible side effects (e.g., changing brightness on a watchface), or any required permissions. The description is too minimal.

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 very concise (one short sentence), but it sacrifices clarity. It is front-loaded but does not effectively communicate purpose or behavior.

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?

Given the tool has a nested parameter (target) and no output schema, the description is incomplete. It should explain the effect of setting brightness, any constraints, or return behavior. Currently, it leaves major gaps.

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 coverage is 50% due to the 'brightness' parameter lacking description. The description adds no meaning for 'brightness' beyond what the schema provides. The 'target' parameter is already described in the schema, so the description offers no additional value.

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 'Call Channel/SetBrightness with Brightness' is vague and does not clearly state what the tool does. It repeats the name without explaining the action in user-understandable terms. It fails to distinguish from sibling tools like watchface_get_brightness.

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?

No guidance is provided on when to use this tool versus alternatives. The sibling tools include a get counterpart, but the description does not specify that this is a set operation or any prerequisites.

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