gitlab-ci-mcp

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true, covering safety and idempotency. The description adds valuable context beyond annotations: the 2KB truncation limit per file, the need to use gitlab_get_file for full content, and the tool's primary use case for code-review queries. This enhances the agent's understanding without contradicting annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is well-structured and front-loaded with the core functionality, followed by usage guidelines and examples. Every sentence adds value: the first defines the tool, the second explains its use case, the third clarifies limitations and alternatives, and the examples provide concrete application. No wasted words.

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

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

Given the tool's moderate complexity, rich annotations (read-only, idempotent, etc.), and the presence of an output schema (which handles return values), the description is complete. It covers purpose, usage, limitations, and alternatives, providing all necessary context for an agent to select and invoke the tool correctly.

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

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

Schema description coverage is 100%, with clear documentation for both parameters (mr_iid and project_path). The description does not add significant semantic details beyond what the schema provides, though it reinforces usage with examples like 'mr_iid=42'. This meets the baseline of 3 when the schema does the heavy lifting.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the specific action ('List changed files in a merge request with truncated diffs') and resource ('merge request'), distinguishing it from siblings like 'gitlab_get_file' (for full file content) and 'gitlab_get_merge_request' (for MR metadata). It explicitly mentions the 2KB truncation limit, which further clarifies its scope.

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

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

The description provides explicit guidance on when to use this tool ('Useful for code-review-style queries') and when not to ('Diffs beyond 2KB are truncated — fetch the raw file via gitlab_get_file for full content'). It names the alternative tool ('gitlab_get_file') and includes practical examples that illustrate proper usage scenarios.

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