glass_gesture

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

Discloses key behavioral details: all pointers down at t=0 and up at duration_ms, from==to means held, common patterns like pinch, rotate, swipe. Warns about unsupported backends. Without annotations, this is reasonably transparent.

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 sentences front-load essential info: tool purpose, parameters, usage patterns, and limitation. Every sentence earns its place with zero redundancy.

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 no output schema and complex input, description covers the main points: gesture mechanics, parameter usage, and backend limitation. Lacks detail on return value but acceptable for this tool.

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?

Adds significant meaning beyond schema by explaining how to achieve common gestures (pinch, rotate, two-finger swipe) and clarifying default duration and pointer behavior. Schema has 100% coverage, but description enriches it.

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 explicitly states it performs multi-touch gestures with 2-10 pointers, each a straight from→to segment. It differentiates from siblings like glass_click and glass_drag by focusing on multi-touch patterns.

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?

Provides clear context on when to use (multi-touch gestures) and notes backend limitation: returns Unsupported error if backend lacks multi-touch. Does not explicitly list alternative tools but context is sufficient.

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