qemu_keyboard_key

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

Annotations already indicate readOnlyHint=false and idempotentHint=false, so the mutating nature is covered. The description adds that the event is sent via QMP and usable regardless of guest-agent startup, but it does not disclose side effects, permissions, or how the action values map to key-down/up/press behavior beyond the schema enum.

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 a single sentence with no filler. It front-loads the action and resource, then adds a useful timing qualifier without 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?

For a simple three-parameter tool without an output schema, the description is mostly serviceable, but it leaves an agent to infer valid QMP qcode key values and the precise meaning of the action parameter. It also does not explicitly differentiate from qemu_keyboard_type, so the guidance is not fully 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?

Schema description coverage is 0%, so the description must compensate for undocumented parameters. It clarifies that 'key' is a QMP qcode, but it does not explain the 'action' enum semantics, the default 'press' behavior, or the vm_id requirement beyond its name and schema pattern.

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 ('Send') and identifies a distinct resource ('QMP qcode key event'), clearly stating what the tool does. It also adds lifecycle context ('before or after guest-agent startup'), which helps separate it from text-typing or mouse tools, though it does not explicitly name sibling alternatives.

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 phrase 'before or after guest-agent startup' gives clear timing context and implies the event is sent via QMP rather than relying on the guest agent. However, it does not explicitly state when not to use this tool or name alternatives like qemu_keyboard_type for text entry, so it stops short of full guidance.

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