Send a key press to the browser and report resulting page, network, and console changes.
Press a key or key combo (e.g. "Enter", "Control+A") and report the network/console/url delta it caused.
| Name | Required | Description | Default |
|---|---|---|---|
| keys | Yes | ||
| waitMs | No | settle time after the key press before reporting the delta (default 700ms) | |
| sessionId | No |
Changes observed during successful MCP inspections.
v0.6.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the behavioral burden. It does disclose that the tool performs an actual key press and reports network/console/url changes, which is useful. However, it does not mention potential side effects like form submission, navigation, destructive shortcuts, session context, or the shape of the returned delta.
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 description is a single focused sentence that front-loads the key action and the reported delta. It includes concrete examples and contains no 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 tool with three parameters, no output schema, and no annotations, the description leaves significant gaps: the returned delta structure, valid key encodings, session behavior, and side effects are not explained. It is minimally usable but not complete enough for reliable invocation in varied contexts.
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 schema only describes waitMs; keys and sessionId are undocumented. The description gives examples of keys but does not explain the full supported key syntax, modifier formatting, or sessionId purpose. With schema description coverage at 33%, the description does not fully compensate for the gap.
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 clear imperative action, 'Press a key or key combo', identifies examples like 'Enter' and 'Control+A', and specifies the output as 'network/console/url delta'. This distinguishes it from sibling tools like page_type and page_click, which handle text entry and mouse actions.
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 implies usage for keyboard shortcuts and observing resulting page deltas, but it does not explicitly state when to prefer page_key over alternatives such as page_type or page_fill. No exclusions or when-not-to-use guidance is provided.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.