desktop_key

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

Annotations already declare readOnlyHint=false, destructiveHint=true, and openWorldHint=true, so the mutation and open-world nature is covered. The description adds useful context that a screenshot is returned and that input targets the focused app, but says nothing about permissions, rate limits, or what happens on invalid keys. With annotations carrying the safety profile, this is a modest addition.

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 compact single sentence that front-loads the action and the target. No wasted words, though the trailing screenshot clause could be structured more cleanly.

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?

No output schema exists, and the description partially compensates by noting a screenshot is returned. For a destructive, open-world input tool, it is adequate but leaves the optional capture_max_width parameter and any failure/permission behavior unexplained.

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 0%, so the description must compensate. It does explain the required 'keys' parameter with a concrete example (['Control_L','a']), which clarifies the expected key-name format. However, capture_max_width is left completely undocumented in both schema and description, leaving half the parameters ambiguous.

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+resource: 'Press a key combination in the focused desktop app'. The extra mention of showing a fresh screenshot describes the side effect. It is clear but does not explicitly differentiate itself from siblings like desktop_type or desktop_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?

No explicit when-to-use guidance or routing to alternatives (e.g., desktop_type for text vs desktop_key for combos). Usage is only implied by the verb. An agent must infer it should use this for key combinations, not plain typing.

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