Find open browser tabs by listing their IDs, titles, and URLs. Use a URL pattern to filter and locate specific tabs quickly.
List open tabs with their ids, titles and URLs.
Args: url_pattern: Optional regex; only tabs whose URL matches are listed.
| Name | Required | Description | Default |
|---|---|---|---|
| url_pattern | No |
| 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?
With no annotations, the description carries the burden of behavioral disclosure. It states the operation is to list tabs, implying a read-only action, but does not explicitly confirm no side effects or mention any permissions or failure conditions. The description is adequate but not rich in behavioral detail.
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 concise and well-structured: a single main sentence followed by a parameter explanation. It is front-loaded with the core purpose and has no fluff.
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 explains what is returned and the filter behavior. Since an output schema exists, return value details are not required. It does not mention whether all windows are included or any prerequisites, but for a simple list tool this is minor. Overall, an agent can invoke it correctly with the given information.
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 0%, so the description must compensate. The 'Args' section fully explains the url_pattern parameter: it is optional, expects a regex, and filters results by URL match. This adds significant meaning beyond the schema's type-only definition.
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 clearly states the verb 'List', the resource 'open tabs', and explicitly enumerates the returned fields (ids, titles, URLs). This distinguishes it from sibling tools like activate_tab or read_tab without needing to reference them.
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?
No guidance is given on when to use this tool versus alternatives. It does not mention that this is useful for obtaining tab IDs before activation or reading content, nor does it exclude any scenarios. The sibling list is provided but the description does not reference it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.