get_display_brightness

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and idempotentHint=true, so the agent knows this is a safe read. The description adds no behavioral details beyond the annotations, and since the tool has zero parameters and no output schema, there is little extra behavior to disclose.

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, short sentence with no wasted words. It is front-loaded and appropriately sized for a trivial read operation.

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 tool with safety annotations already present, the description covers the core purpose. However, without an output schema or mention of the return value format (e.g., percentage or 0-255 range), an agent may guess wrong about the result's units, which is a minor gap.

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 schema coverage is 100%, so there is nothing for the description to add. The baseline for zero-parameter tools is 4, and the description is consistent with that.

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 'Get the current screen brightness' clearly states the action (get) and the resource (screen brightness). It is distinguishable from siblings like set_display_brightness and get_monitor_state, though it does not explicitly name them for 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 the tool is used to read brightness without side effects, and siblings include set_display_brightness and get_resolution, providing context. However, it does not explicitly state when to prefer this over alternatives like get_monitor_state or how to interpret the result.

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