touch-browser

by nangman-infra

Overview Schema Source Related Servers Discussions Admin

Rust

Local

Open New Tab

tb_tab_open

Open a headless browser tab for research workflows, with optional immediate navigation to a targeted web page.

Instructions

Create a new headless research tab, optionally opening a narrowed public web target immediately.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "sessionId": "<sessionId>"
    },
    "name": "tb_tab_open"
  }
}

Input Schema

Name	Required	Description
`sessionId`	Yes	The browser session to use for this operation.
`target`	No	An optional URL or target to open immediately in the new tab.
`sourceRisk`	No	The source risk label to attach to the result or citation.
`sourceLabel`	No	The human-readable source label to attach to the result or citation.
`allowDomains`	No	Restrict the operation to this list of allowed domains.

Output Schema

Name	Required	Description	Default
`sessionId`	Yes
`activeTabId`	No
`tab`	No
`tabId`	No
`diagnostics`	No
`result`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed6 schema fields changedv0.7.0Jun 12, 2026

addedInput schema / properties / allowDomains / description

Added value: +"Restrict the operation to this list of allowed domains."

addedInput schema / properties / sessionId / description

Added value: +"The browser session to use for this operation."

addedInput schema / properties / sourceLabel / description

Added value: +"The human-readable source label to attach to the result or citation."

addedInput schema / properties / sourceRisk / description

Added value: +"The source risk label to attach to the result or citation."

addedInput schema / properties / target / description

Added value: +"An optional URL or target to open immediately in the new tab."

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "additionalProperties": false,
+  "properties": {
+    "activeTabId": {
+      "type": "string"
+    },
+    "diagnostics": {
+      "additionalProperties": true,
+      "type": "object"
+    },
+    "result": {
+      "additionalProperties": true,
+      "type": "object"
+    },
+    "sessionId": {
+      "type": "string"
+    },
+    "tab": {
+      "additionalProperties": false,
+      "properties": {
+        "active": {
+          "type": "boolean"
+        },
+        "currentUrl": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "hasState": {
+          "type": "boolean"
+        },
+        "latestSearchQuery": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "latestSearchResultCount": {
+          "minimum": 0,
+          "type": "integer"
+        },
+        "sessionFile": {
+          "type": "string"
+        },
+        "snapshotCount": {
+          "minimum": 0,
+          "type": "integer"
+        },
+        "tabId": {
+          "type": "string"
+        },
+        "visitedUrlCount": {
+          "minimum": 0,
+          "type": "integer"
+        }
+      },
+      "required": [
+        "tabId",
+        "active",
+        "sessionFile",
+        "hasState",
+        "visitedUrlCount",
+        "snapshotCount",
+        "latestSearchResultCount"
+      ],
+      "type": "object"
+    },
+    "tabId": {
+      "type": "string"
+    }
+  },
+  "required": [
+    "sessionId"
+  ],
+  "type": "object"
+}

First observedv0.1.11Apr 15, 2026

TDQS

B3.2/5.0

Behavior2/5

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

With no annotations provided, the description carries full responsibility for behavioral disclosure. It mentions the tab is 'headless' and the target is 'narrowed public web', but lacks details on what happens with the session, whether the tab persists, error handling, or any constraints beyond the input schema.

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

Conciseness4/5

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

The description is a single, front-loaded sentence without any wasted words. It efficiently conveys the core action and optional feature, though it could be slightly more informative without losing conciseness.

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

Completeness3/5

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

Given the tool has 5 parameters, 1 required, and an existing output schema, the description is short but covers the essential purpose. It does not explain return values (though output schema exists) or side effects like resource cleanup or session state changes, leaving some gaps for a tab creation operation.

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?

All five parameters are documented in the input schema (100% coverage), so the baseline is 3. The description adds the phrase 'narrowed public web target' which hints at restriction but does not substantially clarify parameter semantics beyond the schema descriptions.

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

Purpose5/5

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

The description clearly states the action ('Create'), the resource ('new headless research tab'), and the optional behavior ('optionally opening a narrowed public web target immediately'). It effectively distinguishes from sibling tools like tb_tab_close, tb_tab_list, and tb_tab_select, making the purpose unambiguous.

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 provides no explicit guidance on when to use this tool versus alternatives such as tb_open or tb_search_open_top. There is no mention of prerequisites, contexts where the tool should be avoided, or recommendations for specific use cases.

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