unsend_message

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

The description discloses irreversibility (CANNOT be undone), the safety confirm gate, and that LINE allows unsending only your own messages. No annotations provided, so the description fully covers behavioral traits.

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 sentences, no wasted words. The description is front-loaded with the main action and includes safety and behavioral notes efficiently.

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 2-param tool with no output schema, the description is mostly complete. It covers the action, safety gate, and parameter meaning. Could mention error cases but not necessary.

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%, but the description adds context: messageId must be your own and is returned by get_chat_messages; confirm must be true and irreversible. This adds value beyond the 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?

The description clearly states the tool retracts (unsends) one of your own LINE messages for all participants. It uses specific verbs and resource, distinguishing it from sibling tools like send_message or cancel_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?

The description provides usage context: only for your own messages, with a safety confirm gate. It doesn't explicitly list alternatives or when-not-to-use, but the context is clear.

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