get_merge_request_file_diff

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

Although the annotations already declare readOnlyHint and openWorldHint, the description adds valuable context about error behavior (missing resources, invalid identifiers, insufficient permission, rate limits) and parameter format (numeric ID or URL-encoded path). This goes beyond the annotations and clarifies expected outcomes and edge cases.

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 concise, structured in two sentences, and each clause serves a purpose: purpose, usage guidance, error behavior, and parameter guidance. There is no unnecessary verbosity; it is well-organized and easy to parse.

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?

The description covers the tool's purpose, usage context, error scenarios, and parameter format, which is comprehensive for a typical read-only operation. However, the contradiction regarding required fields slightly reduces completeness, as it may confuse the agent about the exact invocation requirements. Overall, it is nearly complete but not perfect.

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?

The schema descriptions cover 100% of parameters, but the description introduces a contradiction: it states 'mergeRequestIid or branchName required' while the schema only marks project_id and file_paths as required. This conflicting guidance could mislead the agent regarding which parameters are mandatory. The general advice about ID/path format adds little beyond the schema, and the contradiction undermines clarity.

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 tool's function: 'Get diffs for specific files from a merge request.' It also distinguishes it from sibling tools by advising to use this for a known resource and to choose list/search tools for discovery. The verb and resource are specific, and the scope is well-defined.

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 explicitly provides when to use and when not to use the tool: 'Use this for a known resource or result; choose the corresponding list or search tool when you need to discover multiple resources.' This is clear, actionable guidance that differentiates it from alternatives.

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