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

Annotations already declare destructiveHint=true, idempotentHint=true, and openWorldHint=true, but the description adds substantive context beyond them: the dry run is the default, the one-click POST only fires when the provider verified the signer's DKIM and the link is on its domain, and it requires the 'execute: unsubscribe' read permission on every plan. This is meaningful workflow and auth disclosure.

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?

Very compact with every clause carrying information (default behavior, condition for POST, fallback, usage restriction, permissions). The telegraphic, run-on phrasing ('else the manual link. Only when the owner asks.') is dense and slightly disjointed but front-loads the dry-run behavior.

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?

With an output schema present, return values need no explanation, and the description covers the dry-run workflow, the conditions for the automated POST, and the required permission. For a destructive, open-world tool the safety posture is adequately conveyed, though a hint about reversibility or irreversibility of the POST could add more.

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%, so the schema already documents all five parameters including account, uid, folder, confirm, and dry_run defaults. The description reinforces dry_run's default and the confirm-from-dry-run flow but adds little syntax or format detail beyond what the schema already provides, so 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 title and description together establish that this tool unsubscribes from mailing lists, and the text names the specific mechanism (RFC 8058 one-click POST vs manual link). However, the lead sentence 'Reads unsubscribe headers' foregrounds the dry-run read behavior rather than the destructive unsubscribe action, which could momentarily confuse an agent about what the tool actually does.

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?

'Only when the owner asks' is an explicit, restrictive when-to-use condition, and the dry-run-default design implicitly guides the intended two-step workflow. It does not name alternative tools (e.g. modify_message, trash_message), so it stops short of full alternative routing.

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