mouse_move

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

The description adds a critical behavioral detail not already in the annotations: the session lock persists and requires a separate vm_unlock call. This is valuable context beyond the idempotent and non-destructive hints.

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 concise sentences with the core action front-loaded. The lock warning is relevant and adds necessary operational context without fluff.

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?

The description covers the main action and the important lock consequence. It omits preconditions (e.g., whether the VM should already be locked) and duration_ms semantics, but given the tool's simplicity and annotation coverage, it is reasonably complete.

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 description reinforces the meaning of x and y as zero-based physical coordinates, which matches the schema descriptions, but it does not explain the optional duration_ms parameter, leaving 33% of parameters undocumented. The schema covers most of the parameter semantics, so the description adds marginal value.

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 action ('Move the mouse') and specifies the exact coordinate system ('zero-based physical pixel coordinate'), distinguishing it from sibling input tools like mouse_click and mouse_drag. The verb and resource are unambiguous.

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?

It provides practical context by noting that the VM remains locked and instructing to call vm_unlock when finished. This gives the agent clear follow-up guidance, though it does not explicitly contrast with alternative input methods.

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