set_appearance

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

No annotations are provided, so the description carries the full burden. It only states the action ('Switch') without disclosing side effects, reversibility, permission requirements, or behavior when multiple devices are connected. For a mutation tool, this is a significant gap.

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, front-loaded sentence with zero waste. It efficiently communicates the core action and object, ideal for quick agent parsing.

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 simple two-parameter tool, the description is minimally sufficient but lacks context about device selection (e.g., when 'serial' is needed) and any prerequisites. Given no annotations or output schema, it could be more complete, but the core action is adequately conveyed.

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% (serial has a description, appearance does not). The description adds no parameter-specific meaning—it does not explain the 'appearance' enum values or the optionality of 'serial'. It fails to compensate for the schema's incomplete coverage.

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 ('Switch') and resource ('the device') with a precise scope ('between light and dark mode'). It unambiguously conveys the tool's function and distinguishes it from unrelated siblings like set_orientation or set_status_bar.

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, and no mention of prerequisites or exclusions. While the purpose is clear, there is no explicit context for selection among the many sibling tools.

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