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

Annotations only say it is a non-destructive, non-idempotent, open-world write. The description goes well past them: exactly one email per order plus one allowed resend, a 7-day link validity window, no charge or order being placed, the email's subject line, and the instruction to tell the user to check spam. These are the operational constraints an agent cannot infer elsewhere.

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?

Front-loaded with the action and the non-action, then prerequisites and follow-up. The verbatim German consent sentence is long but operationally purposeful; overall density is high with little redundancy, though the paragraph could be broken into shorter units.

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?

An output schema exists, so return values need no explanation. For a send-an-email tool with 5 required parameters, the description covers consent, the source of the price, delivery limits, link expiry, and post-call user guidance — nothing an agent needs 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 coverage is 100% and the property descriptions already carry the important nuance (use the address the customer gave, not one from memory; keep order_token private). The description only restates which inputs are needed in prose, adding no format or semantics beyond the schema. 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 ('Sends the customer one email with a link to their prepared order on our website') and immediately delimits scope by saying what it does NOT do (no ordering, no charging). This distinguishes it cleanly from siblings like start_order, review_order, and get_certificate.

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 an explicit precondition ('Before calling it, ask the user for permission and tell them the price review_order returned'), names the sibling whose output feeds the consent step, and even supplies the wording for the confirmation question. It also covers the resend case, so the agent knows exactly when and how often to call.

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