mouse_scroll

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

While annotations already indicate the tool is not read-only, not idempotent, and not destructive, the description adds meaningful behavioral context: the VM remains locked after the call and the caller must unlock it. It also discloses a dependency on guest wheel support, which is not visible in the schema or annotations.

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 no filler. The core action is front-loaded, followed by the prerequisite and lock/unlock responsibility. Every sentence earns its place.

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 tool with four parameters and no output schema, the description covers the critical invocation facts: what it does, optional coordinates, guest wheel support requirement, and lock management. It does not specify exact delta semantics or failure behavior if wheel support is missing, but these are partially covered by the schema and the prerequisite statement.

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 high at 75%, and the schema already explains x, y, and vm_name. The description adds modest value by calling delta a 'mouse-wheel delta' and noting coordinates are optional, but it does not clarify delta direction, units, or how negative values behave. This is adequate but not richly informative beyond the schema.

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 uses a specific verb and object: 'Send a mouse-wheel delta at optional coordinates.' This clearly distinguishes it from sibling input tools like mouse_move, mouse_click, and qemu_keyboard_type. The 'Requires guest wheel support' caveat further clarifies the intended domain without ambiguity.

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 names the main prerequisite ('Requires guest wheel support') and provides explicit follow-up guidance ('call vm_unlock when finished'). It does not explicitly name alternative tools for when wheel support is unavailable, but the context is clear enough for an agent to decide when to invoke it.

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