click

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the action and coordinate system, but does not mention side effects, return values (e.g., whether a screenshot is returned), or prerequisites like window focus or timeouts. It is not misleading but very minimal.

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 two sentences, with the core action front-loaded. It includes parameter details in a compact format without any redundant text. Every sentence earns its place, making it appropriately concise and well-structured.

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 the simplicity of a click tool and no output schema, the description covers the essential action and key parameters. However, it omits potential context such as what happens after the click (does it capture a screenshot?), whether the cursor is moved, and any error conditions. For a tool with no annotations, this is a moderate gap but not severe.

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 clarifies the meaning of x and y by specifying they are in screenshot-image coordinates, and it explicitly explains button ('left', 'right', 'middle') and count ('2 for a double-click'). However, the screenshot parameter is not explained, and the count semantics beyond 2 are unspecified. Overall, it adds meaningful value to most parameters.

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 ('Click') and a coordinate system ('screenshot-image coordinates'), which clearly identifies the tool's purpose. It distinguishes from sibling tools like move, drag, or scroll by focusing on a simple click action, though it does not explicitly name an alternative. The mention of button and count further specifies the behavior.

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 like click vs. double-click via count, or when to use drag or scroll instead. It does not mention any exclusions or preferred contexts. The only usage hint is the parameter explanation, but that is about how to invoke, not when.

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