reply_to_mr_discussion

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

With no annotations, the description carries the full burden. It discloses the operation is a reply (write action) and explicitly requires write permissions (GITLAB_READ_ONLY=false and api-scoped token). It gives workflow context ('Fecha o loop: ler threads, responder') but does not describe side effects or failure modes, which prevents 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 description is compact, front-loaded with the core purpose, and every sentence provides distinct value: purpose, parameter source, workflow loop, sibling alternatives, and required permissions. 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 (4 required params, no output schema, no annotations), the description covers input sourcing, alternatives, and prerequisites. It does not describe the return value or post-condition, but the tool's purpose is clear enough for an agent to invoke it successfully.

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%, so the schema already documents all four parameters. The description adds minimal new info beyond the schema: 'Pegue o discussion_id em list_mr_discussions' is already embedded in the schema's discussion_id description. The baseline of 3 applies because 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 opens with a specific verb-resource pairing: 'Responde numa thread de comentário já existente do merge request.' It clearly distinguishes from siblings by naming comment_on_mr_line for new line threads and comment_on_mr for loose comments.

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?

Provides explicit when-to-use vs alternative tools: 'Para abrir uma thread nova numa linha use comment_on_mr_line; para comentário solto use comment_on_mr.' It also instructs to obtain discussion_id from list_mr_discussions and states the required GITLAB_READ_ONLY=false and api-scoped token, making conditions unambiguous.

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