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

The description discloses an important behavioral nuance beyond the annotations: 'Revoking affects new submissions, not already delivered tasks.' Since annotations only state readOnlyHint=false, this added context about the scope and side effects of the mutation is valuable and non-contradictory.

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 description is two tight sentences with no filler. The primary action is stated first, and the crucial scoping nuance about revoked senders is added in the second sentence without redundancy.

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 simple two-parameter permission toggle, the description covers the purpose, the effect of revoking, and the fact that existing tasks are preserved. The presence of an output schema reduces the need to document return values, and no critical missing context is apparent.

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 conveys the meaning of both parameters indirectly ('another mailbox' maps to sender_id; 'grant or revoke' maps to allowed), but does not explicitly map parameter names to their meanings or clarify the true/false semantics of allowed.

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 clearly states a specific action ('grant or revoke') on a specific resource ('another mailbox permission to send you tasks'), making the tool's function obvious. However, it does not explicitly distinguish itself from sibling tools like send_task or request_connection, which would have earned 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 description implies the usage context: use this when you want to control which mailboxes are allowed to send tasks to you. It does not explicitly name alternatives or state when not to use this tool, so the guidance is present but only implied.

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