mcpx

shell_script

Run multi-line scripts in bash, sh, or Python via stdin. Supports strict error handling, timeouts, and environment variables.

Instructions

Run a multi-line script (bash/sh/python) fed on stdin.

With strict and a shell interpreter, set -euo pipefail is prepended so failures abort early.

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": {
      "script": "<script>"
    },
    "name": "shell_script"
  }
}

Input Schema

Name	Required	Default
`script`	Yes
`interpreter`	No	bash
`strict`	No
`timeout`	No
`cwd`	No
`env_json`	No

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0May 19, 2026

TDQS

A3.5/5.0

Behavior3/5

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

With no annotations provided, the description partially covers behavior by noting the strict mode and error handling with set -euo pipefail. However, it omits important details like output capture, error propagation, security implications, or side effects.

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 concise with two sentences, front-loading the core purpose. Every sentence adds value, though additional parameter details might be needed.

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's complexity (6 parameters, script execution), the description lacks coverage of return values, logging, error handling specifics, and environmental setup. An output schema exists but is not described, limiting completeness.

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

Parameters2/5

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

The input schema has 0% description coverage, so the description must compensate. It only clarifies the 'strict' parameter's effect, leaving script, interpreter, timeout, cwd, and env_json unexplained. This adds minimal value beyond the schema defaults.

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 tool runs multi-line scripts via stdin, specifying interpreters like bash/sh/python. This distinguishes it from sibling tools such as shell_exec and shell_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 implies usage for script execution and mentions strict mode behavior, but does not explicitly state when to use this tool over alternatives like shell_exec or ssh_exec, nor when not to use it.

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

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