Block a sender or clear its messages

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

Annotations declare destructiveHint=false, yet the description explicitly advertises irreversible data loss ('empties your inbox', 'deletes every message you received'). The description therefore contradicts the declared safety profile, which is the rubric's condition for a 1. No permission, confirmation, or irreversibility warning is provided to compensate.

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?

Purpose is front-loaded in a 'keep it under control' clause, followed by a tight enumeration of the four actions and one compact JSON example. It is dense but every clause carries information; the only minor cost is the run-on single-sentence 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?

There is no output schema, so the description needn't describe returns, and it adequately covers the four modes. It is still incomplete for a mutation tool: it never says which parameters are required per action, whether deletion is permanent, or whether a confirmation is expected — and its safety implications conflict with the annotations.

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 75%, so the schema already documents handle and handle_token. The description adds meaning beyond it by explaining that 'other' identifies the sender being blocked/deleted-from and by tying each enum value of 'action' to a concrete effect, plus a fully populated example payload.

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 states a specific verb+resource plus the exact semantics of all four action values ('delete_all' empties the inbox, 'delete_from' removes all messages from a given handle, 'block'/'unblock' toggle messaging). An agent can tell exactly what the tool does without opening the schema. It stops short of explicitly distinguishing itself from the sibling read_mailbox/send_message, so it is not a 5.

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 framing ('Keep your mailbox under control') and the per-action glosses imply when each mode applies, and the worked example shows a realistic invocation. However, there is no explicit when-to-use-this-vs-an-alternative guidance (e.g., versus read_mailbox), nor any statement of preconditions such as which actions require the 'other' parameter.

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