Unsubscribe as approved

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

Adds substantial context beyond the annotations: HTTPS requests reach senders' servers and are irreversible, mailto targets instead save an unsent draft in Drafts, sending-off surfaces send_preview_error, one log_id covers multiple targets, and partial=true means the call was interrupted and should be checked before retrying. This goes well past destructive/openWorld/idempotent hints.

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?

Front-loads the critical precondition and stays information-dense, but the return-field enumeration (log_id, count, messages, status, partial, token_consumed, drafts) duplicates what the output schema already declares and makes the block longer than needed.

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 destructive, open-world action gated on a single-use token, the description covers preconditions, side effects, confirmation flow, failure/partial handling, and retry guidance — everything an agent needs to call it safely, even though an output schema exists.

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 one parameter and schema coverage is already 100%, so the baseline is high. The description reinforces that it takes no other argument and that the token is single-use, but that mostly restates the schema text rather than adding new meaning.

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 (unsubscribe from mailing lists named by an approved preview) plus the hard precondition that it only runs on an approved token. An agent can distinguish this from preview_action, apply_rules, or a folder move 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?

Gives explicit when-to-use (only after the user approves a preview_action(action="unsubscribe") token), a when-not with a named alternative (to stop mail without contacting the sender, preview a move to a folder or folder rule), and notes the in-client confirmation step.

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