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

Annotations already declare destructiveHint=true and openWorldHint=true, so the safety profile is covered. The description adds concrete value by warning that double-clicking may execute an action and that the target should be inspected first, tying the destructive flag to actual agent behavior.

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 short sentences, zero waste, with the core action front-loaded and the safety caveat immediately after. Every clause carries information an agent needs.

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 rich annotations, a full-coverage schema, and an output schema, the description covers purpose and risk adequately. It does not mention whether a prior pointer_move/screenshot is expected or how it differs from pointer_click, leaving a small routing gap for a 5-parameter GUI 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?

Schema coverage is 100%, with x/y, button, device, and backend all documented in-schema, so the baseline is 3. The description's 'verified desktop coordinate' mildly reinforces the coordinate semantics but adds nothing about button selection, backend choice, or the device requirement.

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?

States a specific verb and resource ('send a native double-click at a verified desktop coordinate') with a concrete example use case (open a file or application). It is clearly distinct from single-click siblings by name and content, though it never explicitly contrasts itself with pointer_click or ui_click.

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 a when-to-use example and a caution ('Inspect the target first'), which implies usage context. However, it names no alternatives — not pointer_click for single clicks, nor ui_click/computer_click for accessibility-tree-based clicking — so the agent must infer sibling routing on its own.

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