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

Annotations only cover the safety flags (readOnly=false, destructive=false, idempotent=false). The description adds genuine context beyond them: the eligibility gate that can block the call, where to unblock it, and that archiving preserves files rather than removing them. It still doesn't say what happens on a repeat call despite idempotentHint=false, so it stops short of full 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?

Three short sentences, front-loaded with the action and its gate. The middle sentence about dashboard resolution is slightly tangential but earns its place by telling the agent where a blocked call is handled.

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?

An output schema exists, so return values need no explanation, and annotations carry the safety profile. Combined with the eligibility precondition and file-preservation note, an agent has enough to invoke correctly; only the reversibility/repeat-call behavior is left unstated.

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 100%, so mailbox_id, account_id and reason are already fully documented, including the account-authorization and reason-hygiene rules. The description adds no parameter-level detail of its own; baseline 3 applies.

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 ('Archive a mailbox') with a real precondition (archive.allowed eligibility). It implies but never names its siblings, so an agent comparing it to mailbox_unarchive or mailbox_delete_permanently gets no explicit contrast.

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 a precondition for use (archive.allowed eligibility) and a fallback path ('Resolve blocked actions in the dashboard'), which is more than nothing. However it never states when to prefer this over mailbox_unarchive or mailbox_delete_permanently, leaving the key alternative-selection decision to inference.

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