get_merge_request_diffs

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

Annotations already mark readOnlyHint; the description reinforces read-only behavior and adds useful disclosure that missing resources, invalid identifiers, insufficient permission, and rate limits are returned as errors. This goes beyond the structured annotations without contradicting them. It does not describe return shape or volume, so it is not a 5.

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 core purpose is front-loaded and the description is reasonably short. However, it contains boilerplate like 'use required identifiers and pagination fields exactly as documented' and a read-only restatement that duplicates structured annotations, plus an unsupported group_id mention.

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?

It covers purpose, error behavior, identifier format, and read-only safety, which is solid for a read-only tool with no output schema. It is less complete because the required-parameter statement conflicts with the schema and the return value shape is left entirely implicit.

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 coverage is 100%, so the baseline is 3 even without parameter info. The description's extra advice is partly inaccurate: it claims mergeRequestIid or branchName is required, while the schema requires only project_id, and it mentions group_id and pagination fields that are not present. This active mismatch makes the description less useful than the baseline.

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 opening clause names the operation and resource precisely: 'Get the changes/diffs of a merge request'. It also scopes the tool to known resources, which distinguishes it from list/search discovery tools. It never names a specific sibling like get_merge_request_file_diff, so it stops short of a 5.

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 says to use this when the resource is known and to choose a list or search tool for discovery. This provides clear usage context. However, it does not enumerate the closest diff-specific siblings, and some identifier guidance conflicts with the schema, making the guidance not fully reliable.

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