Control tabs in a browser session: list, open, select, or close them by index.
List, open (new), select or close tabs by index.
This tool declares no required parameters. Add optional parameters from the input schema as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {},
"name": "browser_tabs"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| url | No | ||
| index | No | ||
| action | No | list |
Changes observed during successful MCP inspections.
v1.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true, readOnlyHint=false, and openWorldHint=true, so the agent knows some actions mutate and destroy state. The description adds the useful fact that one tool multiplexes four distinct operations addressed by index, but it never says that 'close' is irreversible or that index is mandatory for select/close. No contradiction with annotations.
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 tight sentence with the core purpose front-loaded and zero filler. It is efficient, though the terseness is partly under-specification rather than true compression.
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 four-action multiplexer with zero required parameters, no output schema, and no action/parameter mapping rules, the description is too thin. An agent still cannot tell which parameters are valid per action or how this tool relates to the chrome_* tab siblings.
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 0% and no parameter is required, so the description carries the full burden — yet it only obliquely implies 'index' is the addressing key and 'open (new)' hints that url pairs with the new action. It does not state that url is used only with action='new', nor that index is required for select/close, leaving invalid combinations undocumented.
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 names four concrete verbs (list, open, select, close) and the resource (tabs), plus the addressing mechanism (by index), so an agent immediately understands it is a tab-management multiplexer. It falls short of a 5 because it never distinguishes itself from the closely-overlapping siblings chrome_list_tabs, chrome_new_tab, chrome_switch_tab, and chrome_close_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?
'by index' is the only usage signal; there is no statement of when to pick this tool over the four chrome_* tab siblings, no prerequisites, and no guidance on which action to use in which situation. The four actions are simply enumerated without routing logic.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.