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

Annotations do not include readOnly or destructive hints, so the description carries the burden. It mentions 'real mouse events' but does not explicitly warn about potential side effects like navigation or state changes. The action is inherently interactive but not fully disclosed.

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 succinct, consisting of two sentences that cover the action, method, use case, and click_count behavior. Every sentence adds value without redundancy or unnecessary detail.

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?

With all parameters documented in the schema and no output schema, the description provides sufficient context: what the tool does, when to use it, and how click_count behaves. There is no missing critical information for an agent to invoke it correctly.

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?

The schema covers all 5 parameters with descriptions (x, y, button, session_id, click_count), which is 100% coverage. The description adds no extra parameter semantics beyond what the schema already provides, so the baseline of 3 is appropriate.

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 the tool's action (click at viewport coordinates), the method (real mouse events), and the specific use case (canvas/map surfaces without a DOM element). It is distinct from sibling tools like session_click, which likely target elements.

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 explicitly says when to use this tool: 'For canvas/map surfaces with no DOM element to index.' This provides clear guidance on when it is appropriate versus other click tools, and also explains the click_count behavior for double-clicks.

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