update_merge_request_discussion_note

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

The description goes beyond the sparse annotations (only openWorldHint: true) by disclosing that the tool mutates state, requires project or group permissions, and lists possible error types ('validation, conflict, permission, or rate-limit errors'). It also explains that invalid requests are not silently applied. This adds meaningful behavioral context, though it does not mention idempotency, side effects on threads, or the expected response format.

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 four sentences, each serving a purpose: purpose, usage guidance, behavioral context, and parameter tips. It is front-loaded with the core purpose and avoids redundancy. It could be slightly more concise, but the information density is high 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 mutation tool with six parameters and no output schema, the description covers purpose, usage, behavior, and parameter format. It lacks explicit mention of the return value or specific effects like the 'resolved' parameter, but the schema already covers that. Given the complexity, it is reasonably complete, though a brief note on expected response would strengthen it.

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 baseline is 3. The description adds value by explaining how to provide identifiers: 'provide the numeric ID or complete URL-encoded path described by the schema' and advises to 'use required identifiers and pagination fields exactly as documented.' This helps clarify parameter syntax beyond the schema's simple descriptions, though it does not elaborate on all six parameters individually.

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?

States a specific verb and resource: 'Update a discussion note on a merge request.' It clearly differentiates from create and note tools by saying 'Use this for an existing resource; choose the corresponding create tool for a new resource and a note tool for discussion-only text.' This is a precise and unambiguous purpose that distinguishes it from many similar siblings like update_merge_request_note and create_merge_request_discussion_note.

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?

Explicitly provides when-to-use guidance: 'Use this for an existing resource; choose the corresponding create tool for a new resource and a note tool for discussion-only text.' It also mentions that it 'changes remote GitLab state' and requires permissions, and advises on error behavior. This is clear and actionable for selecting the correct tool among many note-related siblings.

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