Jenkins MCP Server

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List Instances

list_instances

Read-onlyIdempotent

Lists configured Jenkins instances with URLs, token sources, and connection health to verify multi-instance access and troubleshoot configuration issues.

Instructions

List configured Jenkins instances (name, url, description, default, where the token comes from). check_connection=True also pings each instance and reports the Jenkins version or the error, the token's user and groups, whether it has admin rights, and quiet-down (shutdown) mode. reload_config=True re-reads config/jenkins_instances.yaml and config/.env without restarting the server. Also reports configuration problems and the state of the knowledge base.

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": "list_instances"
  }
}

Input Schema

Name	Required	Description	Default
`reload_config`	No
`check_connection`	No

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Nov 1, 2026

TDQS

A4.8/5.0

Behavior5/5

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

Beyond the readOnly/openWorld/idempotent annotations, the description discloses important behavior: check_connection performs network pings and reports Jenkins version, authenticated user, groups, admin rights, and quiet-down mode; reload_config re-reads YAML and .env configuration without server restart. It also states that configuration problems and knowledge-base state are reported, which is meaningful behavioral context not supplied by the annotations.

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 front-loaded with the core listing behavior, then explains each flag in compact conditional sentences. Despite being moderately detailed, every sentence adds operational meaning rather than restating schema or annotations.

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?

Given the simple two-parameter schema, annotations, and presence of an output schema, the description provides enough context for an agent to call the tool correctly. It explains both flags, side effects, and reporting behavior without needing to repeat return-value structure.

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

Parameters5/5

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

Schema description coverage is 0%, so the description must explain the two boolean parameters, and it does: check_connection controls pinging and detailed instance status, while reload_config controls re-reading config files without restart. The implied false behavior is clear from the conditional phrasing.

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 uses a specific verb and resource: 'List configured Jenkins instances,' and enumerates the returned fields (name, url, description, default, token source). This clearly distinguishes it from sibling tools, which focus on jobs, builds, logs, nodes, and knowledge-base content rather than Jenkins instance configuration.

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

Usage Guidelines4/5

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

The description gives clear conditions for the two optional flags: check_connection=True pings each instance, and reload_config=True re-reads configuration files without restarting the server. It does not name alternative sibling tools, but no sibling appears to overlap with listing Jenkins instances, so the usage context is sufficiently clear.

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