sandbox-mcp

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env

Manage persistent environment variables in an isolated sandbox. Set, unset, or list variables that persist across commands.

Instructions

Manage persistent environment variables in a sandbox. Variables persist across all commands (sourced from /etc/profile.d/mcp-env.sh).

Args: action: "set", "unset", or "list" (default: "list") key: Variable name (required for set/unset) value: Variable value (required for set) sandbox: Named sandbox (default "default")

Returns: Current env vars or confirmation.

Tool call template

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": "env"
  }
}

Input Schema

Name	Required	Default
`action`	No	list
`key`	No
`value`	No
`sandbox`	No	default

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Jun 11, 2026

TDQS

A3.7/5.0

Behavior2/5

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

No annotations are provided, and the description does not disclose potential side effects (e.g., overwriting variables, validation errors), error conditions, or authorization requirements. It lacks transparency beyond the basic function.

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

Conciseness5/5

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

The description is concise, uses a clear header sentence, and efficiently outlines parameters and return value. No redundant information.

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

Completeness5/5

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

The tool is simple with 4 optional parameters and no nested objects. The description covers the purpose, parameter roles, persistence behavior, and return value, which is sufficient for an agent to use it correctly.

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 coverage is 0%, so the description must compensate. It explains the meaning of action, key, value, and sandbox, but only minimally. It clarifies that key is required for set/unset and value for set, which adds some value over the schema.

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 it manages persistent environment variables in a sandbox and lists specific actions (set, unset, list). This distinguishes it from sibling tools like exec or spawn.

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

Usage Guidelines3/5

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

The description mentions that variables persist across commands and are sourced from a specific file, but does not provide explicit guidance on when to use this tool versus alternatives or specify prerequisites.

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

Deploy Server

env