GitLab MCP Server

get_merge_request_changes

Retrieve the file diff changes of a merge request. Specify the project path and merge request IID.

Instructions

Get the file changes (diff) of a merge request.

Args: project_path: Full path of the project (e.g., 'group/project') mr_iid: The internal ID of the merge request within the project

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": {
      "project_path": "<project_path>",
      "mr_iid": "<mr_iid>"
    },
    "name": "get_merge_request_changes"
  }
}

Input Schema

Name	Required	Description	Default
`mr_iid`	Yes
`project_path`	Yes

Output Schema

Name	Required	Description	Default
`iid`	Yes
`title`	Yes
`changes`	Yes
`changes_count`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jul 6, 2026

TDQS

A3.6/5.0

Behavior2/5

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

No annotations are present, so the description carries full burden for behavioral disclosure. It only states that it gets diff changes but does not disclose traits such as rate limits, pagination, output size limits, or whether it returns full diffs or summaries. For a diff tool, more transparency would be beneficial.

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 extremely concise: one sentence for purpose and two lines for parameter explanations. No redundant information, and the key action is front-loaded. Every sentence is useful.

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 that there are only two simple required parameters and an output schema exists, the description is largely complete. It explains what the tool does and the parameters. However, it could optionally mention the format of the diff output (e.g., unified diff), but the output schema likely covers that. Still, it's adequate for a tool of this complexity.

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 meaning: it explains project_path as 'Full path of the project (e.g., 'group/project')' and mr_iid as 'The internal ID of the merge request within the project.' This clarifies the format and scope beyond the just the parameter names and types.

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 'Get the file changes (diff) of a merge request,' specifying the verb (get) and resource (merge request changes). This distinguishes it from siblings like get_merge_request (which retrieves MR metadata) and get_merge_request_comments (comments).

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. It does not mention prerequisites, when not to use it, or any context for selection. The sibling list is provided externally but not referenced in the description.

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