Server has 10 tools with consistent naming (verb_noun pattern) and visible input schemas via Zod. However, descriptions are generic and lack LLM-optimization guidance. Parameter descriptions exist but are minimal (avg ~40 chars, below 72-char baseline). Output schemas are defined in code but not documented in tool registration. Error handling is basic (generic 'GitLab API error' messages). No tool annotations (readOnlyHint/destructiveHint). Missing idempotency guidance for write operations. Composition is sound, tools are single-responsibility and chainable via IDs.

• Add tool annotations to each tool registration: mark get_file_contents and search_projects with readOnlyHint=true; mark all create_* tools with destructiveHint=true. This enables LLMs to reason about retry safety and state mutation.
• Enhance error handling: parse GitLab API error responses and return structured errors with actionable guidance. E.g., 'Project not found (404). Try search_projects() to find the correct project ID.' or 'Unauthorized (401). Check that your GitLab token is valid and has the required scopes.'
• Expand tool descriptions to 80-150 characters with selection guidance. E.g., 'Create a new branch from an existing ref (commit/tag/branch). Use this to prepare a feature branch before committing changes. If you need to commit multiple files at once, use create_commit instead.'
• Document output schemas in tool descriptions. E.g., 'Returns a GitLabIssue object with fields: id, title, description, state, assignees, created_at, web_url. Use the id for downstream operations like add_comment.'
• Add idempotency guidance to create_* tools: 'This operation is idempotent, calling it twice with the same parameters will not create duplicates. However, if the project already exists, it will return the existing project without modification.'