Bash MCP Server

bash_exec

Execute a bash command and return its stdout, stderr, exit code, and execution duration.

Instructions

Execute a bash command and return stdout, stderr, exit code, and duration.

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": {
      "command": "<command>"
    },
    "name": "bash_exec"
  }
}

Input Schema

Name	Required	Description
`command`	Yes	The bash command to execute
`cwd`	No	Working directory (defaults to server's cwd)
`timeout`	No	Timeout in seconds (default 30, max 600)
`env`	No	Additional environment variables to set

Output Schema

Name	Required	Description
`stdout`	Yes	Command standard output
`stderr`	Yes	Command standard error
`exit_code`	Yes	Exit code (124 = timeout)
`duration_ms`	Yes	Execution time in milliseconds

Schema Changelog

Changes observed during successful MCP inspections.

Changed4 schema fields changedMay 8, 2026
- addedInput schema / properties / command / description
```
Added value: +"The bash command to execute"
```
- addedInput schema / properties / cwd / description
```
Added value: +"Working directory (defaults to server's cwd)"
```
- addedInput schema / properties / env / description
```
Added value: +"Additional environment variables to set"
```
- addedInput schema / properties / timeout / description
```
Added value: +"Timeout in seconds (default 30, max 600)"
```
First observedv0.1.0Apr 5, 2026

TDQS

A3.5/5.0

Behavior3/5

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

With no annotations, the description carries the full burden. It discloses the return values (stdout, stderr, exit code, duration), which is helpful. However, it omits behavioral details like side effects, error handling, permissions, or security implications, which are essential for a bash execution tool.

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 a single, well-structured sentence that front-loads the action and returns concise, relevant information. Every word serves a purpose with no redundancy.

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 that the output schema covers return values and the schema covers parameters, the description is minimally adequate. However, it lacks critical context about safety, side effects, and usage boundaries, which are important for a potentially dangerous tool.

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 100%, so the baseline is 3. The description does not add any additional meaning about the parameters beyond what the schema already provides; it merely restates the action.

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 verb 'execute' and the resource 'bash command', and lists the return values (stdout, stderr, exit code, duration). It is specific and leaves no ambiguity about the tool's purpose, even without sibling tools.

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 guidance on when to use this tool versus alternatives, nor does it specify any prerequisites or exclusions. For a command execution tool, usage context is critical but absent.

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

Deploy Server

Other Tools

bash_execA