Click

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

Beyond the annotations, the description discloses operational requirements: admin mode, an environment flag, and an external dependency (cliclick). This is useful behavioral context that the annotations alone do not provide, such as installation and permission expectations.

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 sentence that front-loads the core action ('Click at screen coordinates') and then adds only necessary prerequisites. Every phrase earns its place with no filler or repetition.

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 point-and-click tool, the description covers the action and all prerequisites. It does not describe the output or failure behavior, but given the simple input schema and absence of an output schema, this is not a significant 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?

Schema description coverage is 100%, and the description adds no additional parameter-level detail. Since the schema already documents x, y, and button with defaults and semantics, the description does not need to repeat them.

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 'Click at screen coordinates' clearly states a specific verb and resource: it performs a click at a given coordinate. It is easily distinguishable from siblings like move_mouse, drag, and scroll, though it does not explicitly name them.

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 important prerequisites ('Requires admin mode AND MACCTL_ALLOW_INPUT=true, and the cliclick tool'), which helps the agent know when it can be called. However, it does not provide guidance about when to prefer click over alternatives such as key_press, type_text, or open.

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