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

Adds meaningful behavioral context beyond the annotations: the exact functional consequences of unlinking (outbound sending halts, inbox threads become unanswerable) and, crucially, that the Google account stays connected. This is consistent with destructiveHint=false since the unlink is reversible by setting a mailbox again — no contradiction.

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 followed by consequences and scope exclusion. No filler; every sentence adds information an agent needs.

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 mutation tool with no output schema, the description plus annotations cover the essentials: what happens, what does not happen, and where the excluded behavior lives. It does not discuss reversibility explicitly or the confirm guard's role, but the schema handles the latter.

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% and both parameters (app_id, confirm) are fully documented in the schema, including the app_id default behavior. The description adds nothing about parameters, so the 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 ('Remove the project's mailbox link') and implicitly distinguishes itself from the sibling set_project_mailbox, its inverse. An agent can identify the operation 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?

Conveys the operational context (nothing sends, inbox threads cannot be answered until re-set) and carves out an explicit exclusion: disconnecting the Google account happens in the dashboard, not here. It stops short of stating prerequisites or when this is preferable to alternatives, but the scope boundary is clear.

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