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

With no annotations, the description carries full behavioral disclosure. It clearly discloses idempotence for on/off, the wakefulness check, that auto-rotation is disabled for rotate, and the return shape. This goes well beyond the minimal requirement, though it doesn't address permissions or device-level side effects beyond auto-rotation.

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 concise and efficiently structured: a short purpose sentence, action-by-action breakdown, and return signature. Every sentence earns its place, and the most important behavioral details (idempotence, auto-rotation) are front-loaded.

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 3-parameter tool with no annotations and no output schema, the description is complete. It covers all actions, parameter relationships, behavioral quirks, and the return object shape, leaving nothing essential for an agent to infer.

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 100%, so the baseline is 3. The description adds extra meaning by explaining the behavioral consequences of each action value and clarifying that orientation is required only for rotate and ignored otherwise. This adds value beyond the raw enum definitions.

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 a specific verb and resource scope: controlling device screen power state and rotation, with explicit action values and their effects. However, it doesn't explicitly distinguish itself from sibling tools like device_rotate or device_orientation, which could cause an agent to wonder which tool to pick for orientation changes.

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 gives clear context for each action ('on' wakes, 'off' sleeps, 'rotate' sets orientation) but provides no when-to-use guidance relative to alternatives. It doesn't mention that device_rotate or device_orientation might be more appropriate for pure rotation needs, nor does it state when this tool should be preferred.

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