discord_add_reaction

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

The description adds permission requirements and idempotency explanation beyond the annotations (idempotentHint=true). It does not contradict any annotations. The behavioral traits are well disclosed, though rate limits or response behavior could be added.

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?

Three short sentences that front-load the core action, then permissions, then relevant alternatives and idempotency. No wasted words; each 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 simple mutation with no output schema, the description covers purpose, permissions, undo, and idempotency. It lacks an explicit statement about return value, but the completeness is sufficient given the tool's simplicity.

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 the schema already describes the parameters well. The description only implies emoji format ('a single emoji reaction') without adding new semantic detail beyond the schema. Baseline 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 it adds a single emoji reaction to a message as the bot, distinguishing it from sibling tools like discord_remove_reactions and discord_get_reactions. The resource and action are explicitly defined.

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?

It specifies required permissions (Add Reactions, Read Message History), provides a cross-reference to discord_remove_reactions for undo, and notes idempotency. It lacks an explicit statement of when not to use it, but the context is generally clear.

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