List open Brave tabs and focus one by index, URL substring, or title substring. Manage multiple tabs in your existing browser session.
List open Brave tabs (via CDP). Optionally focus one by index, URL substring, or title substring.
| Name | Required | Description | Default |
|---|---|---|---|
| index | No | 0-based tab index from the list | |
| urlIncludes | No | Focus the first tab whose URL contains this | |
| titleIncludes | No | Focus the first tab whose title contains this |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It hints that 'focus' mutates browser state (changing the active tab) but does not state what happens if no tab matches the substring, whether the window is raised, or that listing is read-only while focusing is a side-effecting action.
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 short sentences with zero waste, front-loading the core list behavior before the optional focus behavior.
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 simple 3-optional-param tool with no output schema this is mostly adequate: it says what it returns (tabs) and how focus selects one. The gaps are the lack of annotations explaining side effects and no statement of behavior when a match is absent.
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%, so the parameters are already fully documented. The description merely restates the same three selectors (index, URL substring, title substring) without adding format or matching semantics beyond what the schema provides, 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+resource ('List open Brave tabs') plus the secondary action (focus one) and the mechanism (via CDP). None of the 13 siblings list tabs, so it is distinguishable, but it never explicitly contrasts itself with a related tool, keeping it just below a 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?
'Optionally focus one by index, URL substring, or title substring' implies when the focus parameters apply, but there is no guidance on when to call this versus e.g. browser_navigate/browser_prepare, nor any exclusions or prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.