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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation profile is known. The description adds a genuine behavioral constraint not in the annotations: the owner's permission is immutable. It does not address reversibility or auth requirements, so not a 5.

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 terse sentences, purpose front-loaded, with zero filler. Every sentence carries a distinct, useful fact (action, prerequisite source, constraint).

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?

No output schema exists, and the description is appropriately short for a simple 3-param mutation, covering the key constraint. Minor gaps remain around itemId and whether the change is reversible, but nothing essential to correct invocation is missing.

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 only 33% (only mailbox is documented). The description compensates partially by explaining that permissionId is sourced from list_gdrive_permissions, but itemId receives no explanation in either the schema or the description, leaving the low coverage incompletely filled.

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 action ("take away one person's access") on a specific resource, which cleanly separates it from delete_gdrive_item (removes the item) and share_gdrive_item (grants access). The title reinforces the scope ("Revoke access to a Drive file"). It does not name sibling tools, so it falls just short of 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?

Gives a concrete prerequisite ("Get the permissionId from list_gdrive_permissions") and an explicit exclusion ("The owner's own permission cannot be removed"). That covers when to call and a key when-not condition, though it never contrasts against share_gdrive_item or other access tools.

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