Send keyboard key presses to a Firefox tab to trigger shortcuts, navigate forms, or dismiss dialogs. Supports single keys, combinations, and repeated sequences.
Press keys: 'Enter', 'Tab', 'Escape', 'ArrowDown', 'cmd+a', 'shift+Tab', or several space-separated ('Backspace Backspace Enter'). repeat repeats the whole sequence.
| Name | Required | Description | Default |
|---|---|---|---|
| keys | Yes | ||
| tabId | Yes | Tab id from tabs_context | |
| repeat | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It does explain the 'repeat' parameter's behavior but omits side effects (e.g., whether the keypress requires focus, if there are rate limits, or what happens on invalid keys). For a tool with no annotations, this is a significant gap.
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, well-structured sentence that front-loads the purpose and provides concrete examples. Every word earns its place; there is 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?
The description is sufficient for invoking the tool with valid key sequences and repeat, but lacks any error handling, success/failure signaling, or preconditions (e.g., active tab). Given no output schema and no annotations, an agent may be uncertain about edge cases. It is adequate but not complete.
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 only 33% (only tabId has a description). The description compensates by thoroughly explaining the 'keys' format with examples and defining 'repeat' as repeating the whole sequence. It adds meaning beyond the schema for two of three parameters, though tabId is left to the schema's one-liner.
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 verb and resource ('Press keys') and immediately enumerates valid key names and formats, including multi-key sequences. It clearly distinguishes this low-level keyboard tool from siblings like 'type' (for text) and 'click' (for mouse). The purpose is unambiguous.
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 its usage for keyboard shortcuts and special keys, and the sibling list suggests alternatives for other actions. However, it does not explicitly state when not to use it or name a specific alternative for text entry. The context is clear but exclusions are missing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.