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

Annotations already declare destructiveHint=true and idempotentHint=true, and the description adds concrete consequence detail: the old address is invalidated and messages sent to it are no longer processed. It does not mention permission/plan requirements or what the response contains, but with the safety profile already carried by annotations this is solid added context.

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?

Two sentences, front-loaded with the action and its main side effect. No filler or restated title text.

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 two-parameter mutation with an output schema and full annotation coverage, this is nearly complete: the agent knows what changes, what stops working, and that the new address must be valid email syntax. Only the access requirements and behavior on an already-used name are unaddressed.

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 the schema explains that name is the local part used in the email address. The description adds nothing about parameters beyond implying that a new local part is set, so the minimum-viable score 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 (rename) and a specific resource (a sheet's inbound email address, i.e. the email-to-sheet address), and parenthetically explains what that resource does. It is clear what the tool accomplishes, though it does not explicitly distinguish itself from the closest sibling, inbound_email.regenerate, or from sheet.rename.

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?

Lists hypothetical assistant scenarios rather than giving the agent guidance on when to choose this tool over alternatives. It never says when not to rename or which sibling handles the adjacent case (e.g. regenerate), so usage is implied but not routed.

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