io.github.shigechika/junos-mcp

get_config_diff

Compare current Junos configuration against a selected rollback version to identify changes. Specify hostname and optional rollback ID to retrieve a diff for review.

Instructions

Show configuration difference compared to a rollback version.

Args: hostname: Target device hostname (must exist in config.ini) rollback_id: Rollback version to compare against (0-49, default 1) config_path: Path to config.ini (empty string uses default search)

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": {
      "hostname": "<hostname>"
    },
    "name": "get_config_diff"
  }
}

Input Schema

Name	Required	Description	Default
`hostname`	Yes
`config_path`	No
`rollback_id`	No

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Addedv0.16.2Jul 28, 2026
Removedv0.16.1Jul 27, 2026
First observedv0.1.0May 26, 2026

TDQS

A4/5.0

Behavior3/5

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

No annotations are present, so the description carries the burden. It mentions constraints (hostname must exist in config.ini, rollback_id 0-49) indicating a read-only 'show' operation. However, it does not disclose error behavior, authentication needs, or rate limits, which are important for a tool with no annotation safety hints.

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 with no redundant sentences. It uses clear section headers (Args) and effectively front-loads the purpose. Every sentence provides necessary context.

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

Completeness4/5

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

Given a relatively simple tool and the presence of an output schema (reducing need to describe return values), the description covers purpose, parameters, and key constraints. It could be improved by briefly noting expected behavior if rollback version does not exist or if device is unreachable, but it's largely sufficient.

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

Parameters4/5

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

With 0% schema description coverage, the description adds significant meaning beyond the schema: it explains that hostname must exist in config.ini, rollback_id range (0-49, default 1), and config_path behavior (empty uses default). This clarifies constraints and defaults not evident from types alone.

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 'Show configuration difference compared to a rollback version' with a specific verb and resource. It distinguishes from siblings like 'get_config' (which retrieves current config) and 'compare_version' (generic comparison) by specifying rollback comparison.

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 comparing current config to a rollback version but does not explicitly state when to use this tool versus alternatives like 'compare_version' or 'get_config'. No exclusions or conditions are provided.

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