Send a keyboard key press (e.g., Enter, Tab, Escape) to a specified element or the focused element.
Press a key (Enter, Tab, Escape, ArrowDown, etc.). Optionally target an element by ref; otherwise the focused element receives it.
| Name | Required | Description | Default |
|---|---|---|---|
| key | Yes | ||
| ref | No |
Changes observed during successful MCP inspections.
v0.7.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It discloses that the key goes to the focused element unless a ref is provided, which is key behavioral context. However, it does not mention potential side effects (e.g., navigation triggered by keys), whether it waits for any condition, or how invalid keys/refs are handled. It is adequate but not rich.
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 single sentence that front-loads the action and examples, then explains the ref behavior. Every word earns its place with no redundancy or filler.
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 2-parameter tool with no output schema or annotations, the description covers the essential usage: what the tool does, how to target an element, and the fallback. It doesn't cover edge cases like key validity or post-action state, but these are minor for this low-complexity tool.
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 explains that 'key' is a key name (with examples) and 'ref' is an element target, adding meaning beyond the bare 'string' type. This fully clarifies both parameters, making it easy for an agent to use them correctly.
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 clearly states the action ('Press a key') and the resource (browser), with concrete examples (Enter, Tab, Escape, ArrowDown). It distinguishes itself from typing or clicking by focusing on key presses, which is clear from the context of siblings like browser_type and browser_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?
It explains the ref vs focused-element behavior, which is useful context. However, it does not explicitly state when to prefer this tool over alternatives like browser_type or browser_click, nor does it mention any scenarios where it should not be used. The guidance is implied but not explicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.