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

No annotations are provided, but the description discloses key behaviors: keys are pressed AND released as one action, nothing stays held after the call, an empty list force-releases leftover keys, and it returns 'no HID available' on unsupported devices. This goes beyond the schema to inform the agent of side effects and failure modes.

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?

Dense but well-organized: main purpose first, then parameter details, then behavior, then error case. Every sentence contributes essential invocation knowledge with no fluff or redundancy.

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?

Covers purpose, parameter semantics, behavior, and error condition for a two-parameter tool with no output schema. However, it does not specify what a successful call returns (only the error case), leaving slight ambiguity about the success response.

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?

Although the schema covers both parameters, the description significantly enriches `usages` with USB HID code examples, ordering semantics, chord behavior, and the empty-list special case. This adds substantial value beyond the bare array-of-numbers schema definition.

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?

Clearly states 'Send raw HID keyboard usage codes as real hardware keypresses' and establishes it as the ONLY way to inject true keypresses, modifiers, and shortcuts. This distinguishes it from sibling typing tools and provides a specific verb+resource+scope.

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?

Explicitly contrasts with typing tools ('the typing tools can only type into a focused field'), signaling when raw HID input is appropriate. Gives practical guidance on chord pressing and empty-list force-release, though it does not name specific sibling alternatives or exclusion scenarios.

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