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

Annotations already declare destructiveHint=true and openWorldHint=true, so the external-send and irreversibility profile is partly covered. The description adds genuinely useful context: the draft must be in a confirmed state and recipient/version must be revalidated, implying staleness failure modes. It stops short of saying what happens on a version mismatch or that the send cannot be undone.

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 short sentences, zero filler, with the action front-loaded and the precondition following. Every clause earns its place.

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 destructive, open-world send with three required params and no output schema, the description covers the precondition but omits the consequence of a stale version, whether retries are safe, and what a successful send returns. Annotations carry the safety profile, so this is adequate but thin.

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 carries the burden. It gives meaning to recipientEmail (must be the current recipient) and expectedRowVersion (must be rechecked), and implies id via "confirmed draft," but supplies no format or constraint detail beyond the schema's own validation patterns.

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 and target: "Email a confirmed draft to its customer," which clearly separates it from create_approval_request (creating) and cancel_approval (cancelling). It never names a sibling, so differentiation is implied from the verb rather than made explicit.

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?

"Recheck the current recipient and version before sending" is a concrete precondition (implying an optimistic-concurrency flow), but the description gives no when-to-use versus alternatives guidance and no when-not-to-use case among the many sibling approval tools.

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