reactions_create

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

Annotations already indicate readOnlyHint=false, idempotentHint=true, and destructiveHint=false. The description adds that it adds the bot's own reaction, returns a specific object, explains emoji format (unicode or name:id), and notes URL-encoding handled by @discordjs/rest. This goes beyond the annotations, though it doesn't discuss rate limits or broader side effects.

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 well-structured with bolded sections: Purpose, When to use, When NOT to use, Example, Returns. Each section is concise and informative, with 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 is simple with three required parameters, full schema coverage, and an output schema, the description is complete. It covers return values, emoji input formats, a concrete example, and a limitation. This is sufficient for an agent to invoke 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?

The input schema has 100% coverage with descriptions for all three parameters, including patterns and emoji format. The description adds an example with concrete values and restates the emoji format, but does not significantly add meaning 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 "Add the bot's own reaction to a message," providing a specific verb, resource, and scope. It distinguishes from sibling reaction tools like reactions_delete_own and reactions_list by explicitly limiting the action to the bot's own reaction.

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 provides a "When to use" section with concrete use cases (acknowledge, vote/poll, quick affirmation) and a "When NOT to use" section stating that reacting on behalf of another user is not possible via REST. However, it does not explicitly name alternative sibling tools for other reaction operations, so it lacks explicit exclusions.

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