Add reactions

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

The description adds some behavioral context: it can accept unicode or custom emoji by name and can handle multiple emojis. However, it does not disclose potential side effects (e.g., duplicate reactions) or required permissions. Annotations already indicate non-destructive and non-readonly, so the bar is lower.

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 two short sentences with no redundancy. The first sentence states the primary function, the second elaborates on parameter values. Every word is informative.

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 additive action, the description covers the main functionality but omits details like return value and permission requirements. Given the tool's low complexity and the presence of annotations, it is reasonably complete.

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 adds meaning to the 'emojis' parameter by specifying it can take unicode or custom emoji by name, but the schema already provides a similar description. For other parameters (channel, guild, message_id), the description adds no additional insight. Schema coverage is 75%, so the baseline is adequate.

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 action ('add') and the resource ('reactions to a message'), and distinguishes it from sibling tools like 'remove_reaction' and 'clear_reactions' by specifying it can add multiple emojis at once.

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 does not provide explicit guidance on when to use this tool versus alternatives. It lacks mention of prerequisites, conditions, or when not to use it, leaving the agent without comparative context.

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