Kitsune

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browser_tabs

Destructive

Control browser tabs by listing, opening, closing, or selecting them, and request a user handoff for actions that need approval.

Instructions

Manage tabs; request a handoff.

Input Schema

Name	Required	Description
`url`	No	new: URL.
`index`	No	Tab index (close defaults to current).
`action`	Yes
`reason`	No	request: reason shown to user.
`tab_id`	No	request: ID instead of index.
`confirm_token`	No	request: approval token.

Schema Changelog

Changes observed during successful MCP inspections.

Changed7 schema fields changedv0.7.2Nov 5, 2026

removedInput schema / properties / action / description
```
Removed value: -"Operation to perform"
```

changedInput schema / properties / action / enum

Previous value: -[
-  "list",
-  "new",
-  "close",
-  "select"
-]New value: +[
+  "list",
+  "new",
+  "close",
+  "select",
+  "request"
+]

addedInput schema / properties / confirm_token

Added value: +{
+  "description": "request: approval token.",
+  "type": "string"
+}

changedInput schema / properties / index / description

Previous value: -"Tab index, used for close/select. If omitted for close, current tab is closed."New value: +"Tab index (close defaults to current)."

addedInput schema / properties / reason

Added value: +{
+  "description": "request: reason shown to user.",
+  "type": "string"
+}

addedInput schema / properties / tab_id

Added value: +{
+  "description": "request: ID instead of index.",
+  "type": "integer"
+}

changedInput schema / properties / url / description

Previous value: -"URL to navigate to in the new tab, used for new."New value: +"new: URL."

Changed15 schema fields changedv0.4.0Oct 24, 2026

addedInput schema / $schema

Added value: +"https://json-schema.org/draft/2020-12/schema"

addedInput schema / additionalProperties
```
Added value: +false
```
removedInput schema / properties / action / default
```
Removed value: -"list"
```
addedInput schema / properties / action / description
```
Added value: +"Operation to perform"
```

removedInput schema / properties / confirm_token

Removed value: -{
-  "description": "new/close; see browser_click.",
-  "type": "string"
-}

removedInput schema / properties / force

Removed value: -{
-  "default": false,
-  "description": "close: disarm beforeunload.",
-  "type": "boolean"
-}

removedInput schema / properties / include_active

Removed value: -{
-  "default": false,
-  "description": "list: add active_page, the active tab's browser_snapshot(text=True).",
-  "type": "boolean"
-}

addedInput schema / properties / index

Added value: +{
+  "description": "Tab index, used for close/select. If omitted for close, current tab is closed.",
+  "type": "number"
+}

removedInput schema / properties / raw

Removed value: -{
-  "default": false,
-  "description": "new: bypass the image viewer.",
-  "type": "boolean"
-}

removedInput schema / properties / tab_id

Removed value: -{
-  "description": "close/select (required).",
-  "type": "integer"
-}

removedInput schema / properties / timeout

Removed value: -{
-  "default": 15000,
-  "type": "integer"
-}

changedInput schema / properties / url / description

Previous value: -"new (default about:blank)."New value: +"URL to navigate to in the new tab, used for new."

removedInput schema / properties / wait

Removed value: -{
-  "default": false,
-  "description": "new: wait up to timeout ms for the load; returns tabId, final url and status, or on timeout ok=false, timedOut=true with the tab open.",
-  "type": "boolean"
-}

removedInput schema / properties / window_fields

Removed value: -{
-  "default": false,
-  "type": "boolean"
-}

addedInput schema / required
```
Added value: +[
+  "action"
+]
```

Changed21 schema fields changedv0.3.0Oct 22, 2026

removedInput schema / properties / action / title
```
Removed value: -"Action"
```

addedInput schema / properties / confirm_token

Added value: +{
+  "description": "new/close; see browser_click.",
+  "type": "string"
+}

addedInput schema / properties / force / description
```
Added value: +"close: disarm beforeunload."
```
removedInput schema / properties / force / title
```
Removed value: -"Force"
```

addedInput schema / properties / include_active

Added value: +{
+  "default": false,
+  "description": "list: add active_page, the active tab's browser_snapshot(text=True).",
+  "type": "boolean"
+}

addedInput schema / properties / raw / description
```
Added value: +"new: bypass the image viewer."
```
removedInput schema / properties / raw / title
```
Removed value: -"Raw"
```

removedInput schema / properties / tab_id / anyOf

Removed value: -[
-  {
-    "type": "integer"
-  },
-  {
-    "type": "null"
-  }
-]

removedInput schema / properties / tab_id / default
```
Removed value: -null
```
addedInput schema / properties / tab_id / description
```
Added value: +"close/select (required)."
```
removedInput schema / properties / tab_id / title
```
Removed value: -"Tab Id"
```
addedInput schema / properties / tab_id / type
```
Added value: +"integer"
```

addedInput schema / properties / timeout

Added value: +{
+  "default": 15000,
+  "type": "integer"
+}

removedInput schema / properties / url / anyOf

Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]

removedInput schema / properties / url / default
```
Removed value: -null
```
addedInput schema / properties / url / description
```
Added value: +"new (default about:blank)."
```
removedInput schema / properties / url / title
```
Removed value: -"Url"
```
addedInput schema / properties / url / type
```
Added value: +"string"
```

addedInput schema / properties / wait

Added value: +{
+  "default": false,
+  "description": "new: wait up to timeout ms for the load; returns tabId, final url and status, or on timeout ok=false, timedOut=true with the tab open.",
+  "type": "boolean"
+}

addedInput schema / properties / window_fields

Added value: +{
+  "default": false,
+  "type": "boolean"
+}

removedInput schema / title
```
Removed value: -"browser_tabsArguments"
```

Changed5 schema fields changedOct 19, 2026

addedInput schema / properties / action

Added value: +{
+  "default": "list",
+  "enum": [
+    "list",
+    "new",
+    "close",
+    "select"
+  ],
+  "title": "Action",
+  "type": "string"
+}

addedInput schema / properties / force

Added value: +{
+  "default": false,
+  "title": "Force",
+  "type": "boolean"
+}

addedInput schema / properties / raw

Added value: +{
+  "default": false,
+  "title": "Raw",
+  "type": "boolean"
+}

addedInput schema / properties / tab_id

Added value: +{
+  "anyOf": [
+    {
+      "type": "integer"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Tab Id"
+}

addedInput schema / properties / url

Added value: +{
+  "anyOf": [
+    {
+      "type": "string"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "title": "Url"
+}

First observedv0.1.0Oct 16, 2026

TDQS

C2.5/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare destructiveHint=true, readOnlyHint=false, and openWorldHint=true. The description adds little beyond that: it does not explain what gets destroyed on close, what a "handoff" or approval token entails, or what authorization/preconditions apply to tab selection.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness3/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is short and front-loads the resource, but "request a handoff" is cryptic and does not earn its place without further explanation. This is under-specification rather than effective conciseness.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a five-action, destructive, open-world tab-management tool with six parameters and no output schema, the description is far too thin. It leaves the request/handoff flow, approval token, and action-specific behavior to inference from the schema alone.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 83%, so the baseline is 3. The description adds no parameter-level meaning beyond the schema; "request a handoff" only vaguely gestures at the request action and confirm_token/reason fields.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose3/5

Does the description clearly state what the tool does and how it differs from similar tools?

"Manage tabs" gives a generic verb and the resource, but the actual operations (list/new/close/select/request) are only discoverable from the action enum in the schema. "Request a handoff" is unexplained, and there is no differentiation from siblings such as browser_navigate, browser_close, or browser_resume.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description offers no explicit when-to-use guidance, no exclusions, and no alternatives. At best, "request a handoff" hints at a request action scenario, but an agent cannot tell when this tool should be selected over browser_navigate or browser_close.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

browser_tabs

Instructions

Input Schema

Schema Changelog

TDQS

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