Add issue reaction

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

Annotations already declare readOnlyHint=false and destructiveHint=false, covering the mutating but non-destructive nature. The description adds no additional behavioral context such as permission requirements, idempotency characteristics, or side effects beyond what annotations reveal.

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 a single, front-loaded sentence that conveys the essential purpose without extra words. It fits the tool's simplicity and leaves parameter details to the schema. No unnecessary content.

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 is adequate for a straightforward write operation with a known output schema. It covers the core usage (issue or comment) and effectively communicates the scope. It doesn't mention edge cases like duplicate reactions, but given the output schema and annotations, this is acceptable.

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 description's phrase 'or to one of its comments' clarifies that the optional note_id parameter refers to a comment, which is not explained in the schema (note_id has no description). This adds meaning beyond the 75% schema coverage, which describes name, project, and issue_iid.

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 specific action: adding an emoji reaction to a GitLab issue or a comment. It distinguishes from siblings like add_merge_request_reaction (which targets MRs) and remove_issue_reaction (which removes reactions). The verb 'add' and resource 'emoji reaction' are explicit.

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 specifies the target being either an issue or its comments, which clarifies when to use this tool. It does not explicitly name alternatives or state when not to use it, but the scope is clear from the context and sibling tool names.

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