cyd_tap

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

No annotations are provided, so the description carries the burden. It discloses that the tap is 'synthetic' and 'queued' (not immediate), and specifies the coordinate system ('absolute 320x240 display coordinate'). However, it doesn't disclose whether the tap is injected at the OS level, whether it requires a foreground app, or what happens if coordinates are out of bounds (though schema enforces bounds).

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?

One sentence, front-loaded with the key qualifiers ('Machine-specific', 'Action, L0', 'synthetic tap', 'absolute 320x240 display coordinate'). Every word earns its place; no filler.

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 2-parameter tool with no output schema, the description is mostly complete. It covers the action, coordinate space, and queued nature. Gaps: no mention of return value/acknowledgment, no mention of whether the tap is injected immediately or batched, and no mention of any prerequisites (e.g., device must be awake). These are minor for a low-level action but would help an agent.

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 description coverage is 0%, so the description must compensate. It explains that x and y are absolute display coordinates in a 320x240 space, which adds meaning beyond the raw integer schema. However, it doesn't clarify units (pixels), origin (top-left?), or whether the coordinates are relative to the display or the current app.

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 states a specific verb ('Queue a synthetic tap') and resource ('absolute 320x240 display coordinate'), which clearly distinguishes it from sibling tools like cyd_key_press or cyd_type_text. It doesn't explicitly name a sibling alternative, but the action is unambiguous.

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 when to use it: when a synthetic tap at a display coordinate is needed. It doesn't explicitly state when not to use it or mention alternatives like cyd_touch_calibrate_start for calibration, but the context is reasonably clear for a low-level action tool.

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