Simulates pressing a single keyboard key or combination, such as Enter, Escape, Control+A, or PageDown, to trigger browser interactions and navigation.
Press a key or combo, e.g. Enter, Escape, Control+A, PageDown.
| Name | Required | Description | Default |
|---|---|---|---|
| key | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare that the tool is not read-only, may interact with an open world, and is not destructive. The description adds only key-format examples and does not explain where the keypress is directed, whether it can trigger navigation or dialogs, or any other side effects beyond what annotations provide.
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 definition is a single short sentence with no filler. The action is front-loaded and the examples are compact while still clarifying the parameter format.
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?
An output schema exists, so return values need not be explained. However, for a browser key-press tool, the description should clarify focus requirements and typical outcomes. It is minimally adequate but leaves meaningful contextual gaps.
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?
The single parameter has 0% schema description coverage, so the description must carry the burden. It usefully gives examples of valid key values and combo syntax, but it does not document modifier ordering, accepted key names beyond the examples, or whether case matters.
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 states a specific action and resource: pressing a key or key combination. It gives concrete examples such as Enter, Escape, Control+A, and PageDown, making the purpose clear. It does not explicitly differentiate itself from siblings like type_text or click, which prevents a 5.
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 description provides examples of key values but gives no guidance on when to use this tool instead of alternatives such as type_text, click, or fill_form. It also omits prerequisites like ensuring the right element is focused before pressing a key.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.