cancel_reaction

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

Discloses scope (this account's reaction), undo behavior (undoes react_message), and limitation (one per call). No annotations provided, so description carries burden and does it well.

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?

Two concise sentences with all essential info: action, scope, relation to sibling, usage constraint. 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?

For a simple one-parameter tool with no output schema, description is fully informative: purpose, behavior, parameter source, usage patterns, and limitations.

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?

Only parameter messageId has schema description, which is 100% covered. Description adds context 'as returned by get_chat_messages', improving usability beyond schema.

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?

Clear verb 'Removes' and resource 'this account's reaction'. Distinguishes from sibling 'react_message' by stating 'Undoes a react_message'.

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?

Explicitly links to react_message as undo. Mentions 'One cancellation per call' implying usage constraint. No explicit when-not-to-use, but context is clear.

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