Captures the Safari window as an image, bringing it to the front first; requires Screen Recording permission.
Screenshot the Safari window (brings it to the front). Needs Screen Recording permission.
| Name | Required | Description | Default |
|---|---|---|---|
| tab | No | Tab id "windowId:tabIndex" from tabs_list. Omit for the active tab of the front window. |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and does disclose two non-obvious behaviors: it brings the window to the front (a focus-stealing side effect) and it requires Screen Recording permission (a likely failure mode). It omits what the call returns — image content versus a file path — which matters for a screenshot tool.
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?
Two compact parenthetical sentences with zero waste. The action is front-loaded and both supplementary facts (fronting behavior, permission need) earn their place.
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 permission prerequisite and side effect cover the main failure modes, but with no output schema the description never indicates the return format — whether the agent receives image data, a path, or metadata. For a screenshot tool that is a meaningful gap in an otherwise lean definition.
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 description coverage is 100% and the single 'tab' parameter is fully documented in the schema, including the 'omit for active tab' default. The description adds nothing about the parameter, so the baseline of 3 applies.
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?
States a specific verb and resource: 'Screenshot the Safari window.' An agent can tell this captures a visual image, distinct from text-extraction siblings like get_page_text or read_page. It does not explicitly name those siblings as alternatives, keeping it at 4 rather than 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?
Usage is only implied by the scope ('the Safari window') — the agent must infer that this is the tool for visual capture rather than page content. No explicit when-to-use or when-not-to-use guidance is given, and no alternative tools are named.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.