click

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

Annotations already declare destructiveHint=true, readOnlyHint=false, and openWorldHint=true, so the agent knows this mutates guest state. The description adds the useful detail that the host pointer is untouched, which is behavior beyond the annotations, but it says nothing about what the click affects in the guest, coordinate origin, or default button.

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?

A single short sentence, front-loaded with the action and immediately followed by the key constraint. There is no filler, though the brevity comes at the cost of the missing parameter detail noted above.

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 destructive, four-parameter tool with zero schema description coverage and no output schema, the description is far too thin. An agent cannot determine click count, button, coordinate frame, or any prerequisite session state without guessing.

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% across four parameters, so the description must carry the semantics and largely does not. 'Guest pixel' weakly implies that x/y are pixel coordinates in guest space, but count (1 vs 2 clicks), button (left/middle/right), and default values are never mentioned.

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 target: 'Click a guest pixel', and adds a differentiating clause ('without moving the host pointer') that separates it from the sibling 'move' tool. It is clear what action occurs, though 'guest pixel' assumes knowledge of the guest/host coordinate split.

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 no explicit when-to-use guidance, no preconditions (e.g. whether a session must be started first via 'start'), and does not name alternatives such as 'move', 'type', or 'key'. The only implicit routing signal is the contrast with host-pointer movement.

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