discord_add_reaction

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

Annotations already indicate read intent (false), idempotency (true), and destructive (false). The description adds value by explaining the bot's perspective, permission needs, and the specific idempotency behavior. No contradictions with annotations.

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 highly concise with only three sentences, each serving a distinct purpose: purpose, permissions, and idempotency/undo. No redundancy or filler, and the key information is front-loaded.

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 simplicity (3 parameters, no output schema), the description covers core aspects: action, permissions, idempotency, and undo suggestion. It could mention error scenarios or message existence, but the provided information is sufficient for an AI agent to use the tool correctly.

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 has a clear description in the schema. The tool description does not add any additional parameter semantics beyond what is already in the schema, so baseline score of 3 is appropriate.

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 a single emoji reaction to a message as the bot.' It specifies the verb (add), resource (emoji reaction), and actor (bot). It also distinguishes from sibling tools by mentioning 'Use discord_remove_reactions to undo,' giving clear differentiation.

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 provides permissions requirements ('Add Reactions and Read Message History') and explains idempotency, guiding appropriate use. It also names the undo tool. While it doesn't cover all alternatives (e.g., get_reactions), it gives sufficient context for the tool's typical usage.

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