get_merge_request_discussion

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

The description states read-only behavior, matching the readOnlyHint annotation, and goes beyond annotations by specifying error outcomes: invalid identifier, missing discussion, or insufficient permission. It does not detail the response shape, but the error semantics add useful operational context.

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?

Three short sentences: purpose, usage/alternative routing, and behavior/errors. The most important scoping information is front-loaded and every sentence earns its place.

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?

For a simple 3-parameter read-only tool with no output schema, the description covers selection, invocation context, and likely error cases. It does not describe the discussion item structure, but that is not necessary for correct invocation.

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% and each parameter already has a clear description (project ID or encoded path, thread ID, MR IID). The tool description adds little beyond saying the discussion is fetched 'by discussion identifier,' so the schema carries the parameter-meaning burden.

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 'Get a single discussion item for a merge request' names a specific verb, resource, and singular scope. It further clarifies the target by contrasting with `mr_discussions` (collection) and `get_merge_request_note` (flat note), making the tool distinguishable from siblings.

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?

It explicitly says to use this tool for 'one known merge request discussion by discussion identifier' and directs the agent to `mr_discussions` for a collection and `get_merge_request_note` for a flat note. This is direct when/when-not guidance with named alternatives.

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