Tap

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

While annotations correctly flag openWorldHint=true and readOnlyHint=false, the description adds no behavioral context about what occurs when invoked (e.g., whether DOM keyboard events are dispatched, if the target element requires focus, or how long the key is held).

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 three-word sentence is technically brief, but it constitutes under-specification rather than effective conciseness, as it adds no actionable information beyond the tool name itself.

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?

Given two undocumented parameters and no output schema, the description is inadequate. It omits critical implementation details needed for correct invocation, such as modifier bit flags or key string formats.

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?

With 0% schema description coverage, the description completely fails to compensate by explaining acceptable 'key' values (key codes, single characters, special keys) or the integer bitmask expected for 'modifiers'.

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 'Press a key.' merely splits the camelCase tool name into words, functioning as a tautology. It fails to distinguish this tool from siblings like 'tap_type' (for text strings) or 'tap_click' (for mouse actions) by specifying scope or keypress semantics.

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 guidance is provided on when to use single key presses versus 'tap_type' for character input, nor are prerequisites (like element focus) or modifier key combinations explained.

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