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

The annotations already declare openWorldHint, destructiveHint, and idempotentHint=false, so the risk profile is largely covered. The description adds useful context that the send is gated on the owner's approval, but it is ambiguous whether the tool blocks until approval or sends immediately, and it doesn't warn about duplicate sends or what happens when approval is denied.

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, front-loaded with the core action and followed by the key gating constraint. Nothing is wasted.

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 non-idempotent, externally visible send with no output schema, the description covers the action and the approval gate but leaves open the return behavior and error/denial handling. Adequate but with clear gaps.

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 80%, so the schema already documents defaults for 'to', 'message', and 'subject'. The description adds no parameter-level meaning beyond that, making the baseline 3 appropriate.

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 uses a specific verb and resource ('Approve the quote and email it to the customer') and explains the accept/decline link, so the agent knows exactly what the tool does. It doesn't explicitly contrast with close siblings like send_invoice, but the quote-specific framing makes the distinction reasonably clear.

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?

'Waits for the owner's approval' implies the context in which this tool runs, but there is no explicit when-to-use vs. when-not guidance and no mention of alternatives such as send_invoice or create_invoice_from_quote. Usage is implied rather than stated.

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