feat: Gitlab list repository tree tool

[BobMerkus]

This PR adds a list_repository_tree tool for the Gitlab MCP, so AI agents can explore repositories interactively.

Description

This PR adds a list_repository_tree tool for the Gitlab MCP, so It can explore a repository interactively. It wraps around the corresponding List repository tree.

Server Details

• Server: gitlab
• Changes to: tools

Motivation and Context

The AI agents are in the dark regarding the structure of a repository and can only read specific files in their entirety. This PR adds the list_repository_tree to allow the AI to explore the repository before reading/updating specific files.

How Has This Been Tested?

Yes, have tested locally using Claude Sonnet 3.7

Breaking Changes

No

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Protocol Documentation
• My changes follows MCP security best practices
• I have updated the server's README accordingly
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have documented all environment variables and configuration options

Additional context

See List repository tree - Gitlab Documentation.

Get a list of repository files and directories in a project. This endpoint can be accessed without authentication if the repository is publicly accessible.

This command provides essentially the same features as the git ls-tree command. For more information, refer to the section Tree Objects in the Git internals documentation.

Attribute	Type	Required	Description
id	integer or string	yes	The ID or URL-encoded path of the project.
page_token	string	no	The tree record ID at which to fetch the next page. Used only with keyset pagination.
pagination	string	no	If keyset, use the keyset-based pagination method.
path	string	no	The path inside the repository. Used to get content of subdirectories.
per_page	integer	no	Number of results to show per page. If not specified, defaults to 20. For more information, see Pagination.
recursive	boolean	no	Boolean value used to get a recursive tree. Default is false.
ref	string	no	The name of a repository branch or tag or, if not given, the default branch.

[olaservo]

Thanks for contributing this PR. This server has been moved to the archived repository at https://github.com/modelcontextprotocol/servers-archived to reduce maintenance overhead, so we can focus our efforts on a smaller set of core servers.
Since we're no longer accepting contributions to this server, we won't be able to merge this PR. If you're interested in contributing similar functionality, we recommend checking out the alternatives listed in the Readme.