unsend

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

Annotations already declare destructiveHint=true, so the safety profile is covered. The description adds real value beyond that by specifying the destruction scope ('for everyone') and noting it also covers messages the owner sent from their phone, which is non-obvious behavioral context.

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 core action is front-loaded in a tight first sentence, but the middle paragraph is conversational and rambling ('That covers yours and the ones the owner sent from their phone: when the operator tells you to delete one, do it'), and the awkward line breaks dilute structure.

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?

Output schema exists, so return values needn't be described. The description covers action, scope, id source, and target semantics for a two-parameter destructive tool; only permission requirements and irreversibility confirmation are absent.

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 description coverage is 0%, so the description must compensate. It explains the 'to' parameter meaningfully (chat alias, omit to target the sole subscribed target), but the message_id entry ('Id of the message') merely restates the schema title, leaving the more useful detail to the get_message_ids cross-reference.

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?

States a specific verb and resource ('Unsend a message this account sent') plus scope ('for everyone'), which distinguishes it from send/reply siblings. An agent knows exactly what operation this is without opening the schema.

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?

Routes the agent to get_message_ids for the required id and states when to act ('when the operator tells you to delete one, do it'). It gives clear triggering context but no explicit when-not guidance or comparison against alternatives like hide_thread.

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