Opens a URL in the browser, creating a new page if none exists, otherwise navigating the active tab.
Open a URL in the browser. Creates a page if none exists; otherwise navigates the active tab.
| Name | Required | Description | Default |
|---|---|---|---|
| url | Yes | Full URL to open (https://...). |
| 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?
No annotations are provided, so the description carries the full disclosure burden. It does disclose the key side-effect: conditional page creation versus active-tab navigation. It does not mention loading or waiting behavior, but for a simple one-parameter navigation tool this is reasonably transparent.
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 concise sentences with no wasted words. The first states the core action, and the second adds the essential conditional behavior, making the definition easy to parse quickly.
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 one-parameter tool with an output schema, the description covers the essential behavior: open a URL and what happens with or without an existing page. A brief pointer to browser_tab_new for forced new-tab behavior would improve completeness, but it is not strictly required for correct calling.
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 already provides 100% coverage for the single url parameter, so the baseline is 3. The description's 'Full URL to open' largely echoes the schema's property description and adds no additional semantic detail.
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 uses a specific verb and resource: 'Open a URL in the browser.' It also distinguishes its behavior from related tools by explaining that it creates a page if none exists and otherwise navigates the active tab.
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?
There is clear behavioral context: a page is created only if none exists, otherwise the active tab is navigated. However, it does not explicitly mention when to prefer browser_navigate over siblings like browser_tab_new, browser_go_back, or browser_go_forward, so guidance on alternatives is only implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.